Thank you, Iris. I'm pleased to deliver today's opening remarks on behalf of Mr. Zhou Yuan, Founder and CEO of Zhihu. Hello, everyone. Thank you for joining Zhihu's first quarter 2023 earnings call. We are delighted to start 2023 with a solid first quarter highlighted by sustaining the revenue growth and a significantly narrowed net loss, both beating the market consensus. While continuously expanding our user base over the past two years, we have also been closely following and capturing the evolving demand for short-form online reading, including both knowledge sharing and notebooks. In addition to the various Yan Selection membership services, we launched a new app Yanyan Stories in major app stores recently to serve the broader user content demand as a part of Zhihu's product metrics. Yanyan Stories will not only contain content generated from the Zhihu community, but also provide more differentiated content. Moreover, Yanyan Stories will cover users from different tier cities and support more audio books, by offering more effective assistance for content creators. The installations are bouncing the premium content, compared with our widely recognized brand name, compared to the number of average monthly subscribing members to a record high of 14.9 million in the first quarter, representing 116% year-over-year and 14.5% sequential growth respectively. We also continued to advance our technological development during the quarter, through a combination of internal initiatives and the joint development efforts, as we actively explored the possibilities, and potential of revolutionary AI technology. Zhihu is now equipped with large language model technology that has 20 billion parameters. We launched our first language with large language model, or LLM, Zhihaitu AI in April, aiming to enable our content creators to generate high quality content more efficiently. Additionally, our users may utilize our LLM summarization function to consume more content and accelerate their readings in a more enjoyable way. At the beginning of 2023, we optimized our organizational structure by combining advertising and content-commerce solutions, or CCS, to enhance the overall competence and operational efficiency of our combined marketing services business. This upgrade has empowered us to better utilize resources within the Zhihu community and provide our clients with a more effective and comprehensive marketing solutions. As we optimize our marketing services business, I will personally spend more time on the segment and the monetary exclusion. Starting from the recent months, we have already seen a revival of advertisers' engagement in e-commerce and 3C factors. We are confident that our marketing services will achieve sequential growth in the second quarter and pickup growth momentum in the second half of the year. Now, let me move on to our users and accountants where we have made a remarkable progress, especially in our short-form content. In the first quarter, we continued to broaden our content coverage, and deepen our penetration across our cornerstone verticals, optimizing our content composition, and format to better satisfy users' evolving needs to used their fragmented time efficiently and obtain information quickly. To that end, we significantly upgraded our [ideas tab] or [ITT], making a short form content pool to complement the long-form knowledge-based content currently available in Zhihu's community. We also expanded our short-form content library to cover more lifestyle and consumption scenarios in response to users' needs. By upgrading an array of tools and functions, such as the picture editor and video caption, among many others, we provided a more efficient scenario to inspire creativity for new content creation. This is making progress in content successfully and saw an increase in the number of users in our community, driving our MAUs in March to more than 110 million. We achieved reacceleration in MAU growth in the first quarter and expect MAUs will grow up to 120 million within 2023 to mark another historical highs. While we remain dedicated to further solidifying Zhihu's leadership with leading positions as a platform for users to discuss and exchange ideas, we are also looking for ways to enhance our offerings by incorporating AI technology within our community. At the Zhihu [Discovery Conference] in April, we introduced our AI strategy, along with our first [indiscernible] Zhihaitu AI. Through investments and joint development efforts, we are accelerating our progress in integrating AI technology across various applications scenario throughout our ecosystem. The trending topics summary is our first trial AI functions. By leveraging AI language learning ability to collect thoughts, and integrated answers, the trending topics summary is able to summarize answers and present them to our users in an intuitive and a clear manner. We're now opening this AI and summarization function to more users via the Zhihu mobile App. By further capitalizing on all unique advantages in both the data layer and application layer, Zhihu is committed to becoming an important to developer and ultimately a leading contributor to the industry's overall developments in this area of AI technology. Next, our membership business. Driven by our premium content offers and continuously expanding brand influence, our pay membership business grew rapidly during the quarter, delivering logos to increases on both an annual and a sequential basis. Paid membership revenue for the first quarter increased by 105.2% year-over-year, while average monthly scribing members grew by 116% year-over-year to 14.9 million in this quarter. We streamline content creation procedures to improve efficiency and enforce the community compliance to protect the content creators' rights and the benefits. As part of a multi-brand strategy, we launched our new ex-U.S. Yanyan Stories, featuring numerous user favorite functions, such as story search, audiobooks, and recommended reading lists. This new app will help us attract more memberships and subscribers begin with the Zhihu community while building a distinct user base, peaking for a more concentrated reading experience inside the Zhihu community and cohort. We hope Yanyan differentiated content will also penetrate the massive Internet users from Tier 2 and Tier 3 cities in China. Now moving on to our vocational training business. Revenue from vocational training business increased by 170.6% year-over-year to RMB107 million in this quarter. We grew our footprint in the vocational training industry value chain by organic growth and the business acquisition. To see the greater potential in the graduate student entrance examination market, we recently completed the acquisition of MBA Masters, a training institution specializing in preparation for MBA entrance examination in China. Completing the integration of MBA Masters, first it enhances our industry competence, with an improved business structure and enrich the service offers. Additionally, we continue to extend our vocational training services across major categories by developing programs that are in high demand in this evolving market, including civil service examination, ESG, judicial examination and story writing, among others. As I mentioned earlier, we are integrating AI technology into our course offerings as we look to enhance the overall quality and user experience. Encouraged by the positive feedback, we have received our first new AI powered program, we will continue to deepen our exploration of innovative technologies. Before I conclude, I'd like to provide a brief update on our ESG efforts. We published our ESG annual report for 2022 last month, presenting Zhihu's longstanding commitment to social responsibility. As a leading online content community in China, our top priority and greatest assets is and will always be our people, our employees, our content creators, our users and our society. Therefore, we strive to improve our ecosystem for each of these stakeholders throughout 2022. With the initiatives including an upgraded leadership development system for employees, our high-end campaign 4.0 incentive plan for content creators, and array of programs to protect and serve our most vulnerable users including minors, those with disabilities and seniors. We also leveraged our wealth of knowledge content to promote childhood education, particularly in new areas that we believe education equality and the growth and the development of China's young generation are critical to Zhihu's progress. Going forward, we will remain committed to our stakeholders, improving their lives as we seek new ways to create value for our society and our planet sustainably. Looking ahead to the rest of 2023, we will remain focused on both monetization and user growth. Marketing services and paid membership have become our major revenue drivers, improving our continued expansion of the vocational training business and an LLM development. We will further expand discussion and research scenarios in the Zhihu community, as we leverage our resources and refine experience to study and respond to the evolving needs, thereby better serving both users and clients. Thanks to our organizational optimization and operational efficiency improvements, in the first quarter, our non-GAAP net loss narrowed to RMB 120 million with adjusted net loss margin narrowed to 12.1%. We expect our business growth will continue accelerating, and we are confident, we will achieve 20% year-over-year increase in MAU as we strive to make innovative breakthroughs. We also believe our passion for progress and dedication will continue to empower our strength and resilience, as we grow in this exciting and dynamic industry. This concludes Mr. Zhou Yuan's remarks. I will now turn to our financial details in the first quarter for review of our first quarter 2023 results. Please see our press release issued earlier today. We were excited to have commenced 2023 with a strong first quarter. Both our top-line and bottom-line meet The Street consensus, while our operating cash flow turned positive for the first time since our initial public offering. Total revenue for the first quarter increased by 33.8% year-over-year to reach RMB994.2 million, effectively beating the market consensus. Our paid membership and vocational training services continued to be exercised in robust growth during the quarter, increasing their contributions to total revenues to 46% and 11% respectively. However, as a variety of market factors continue to affect the overall online advertising market, advertising spending remained sluggish in the first quarter. To mitigate the impact we optimized our organizational structure during the quarter, enabling us to better utilizing our community resources and enhance our service capability by integrating brand advertisements and CCS. Starting from the first quarter, our advertising business is now combined with CCS into marketing services to align with our new strategy and upgrade here the business structure. Our paid membership revenue for the quarter was RMB454.8 million up 105.2% year-over-year from RMB221.7 million in the same period of 2022. Our average monthly subscribing members grew by 116% year-over-year to 14.9 million, which is a record high. Our appealing premium content and outstanding user experience continue to attract the broader user base, even beyond our Zhihu community. The company's marketing services revenue for the quarter with RMB392.1 million. We are encouraged to see some even signs of recovery in our marketing services in the recent months. And we expect our marketing services business to gain faster recovery during the second half of this year. Our vocational training business revenue for the quarter reached one RMB107 million, representing year-over-year increase of 170.6% from RMB39.5 million in the same period of 2022. Moving forward, we will continue to enhance our service capabilities and advance our footprint in an industry with both organic growth and business acquisition. Gross profit for the first quarter increased by 52.7% year-over-year to RMB512.2 million. Gross margin expanded to 51.5% from 45.1% in the same period of 2022, representing more than 6 percentage points expansion, thanks to our enhanced monetization efforts, and the improvements of our cloud services and bandwidth utilization efficiency. We were particularly happy to see our investments in research and development rewarded us with the savings in cloud service utilization. Total operating expenses for the first quarter were RMB729 million down by 25.9% from RMB983.7 million in the same period of 2022. Selling and marketing expenses decreased by 12% to RMB445.6 million, from RMB506.6 million in the same period of 2022. The decrease was primarily due to our disciplined promotion spending and decrease in salaries and welfare expenses for sales and marketing related personnel. In the meantime, the number of Zhihu's MAUs recovered significantly to 110 million in March. We will remain dedicated to driving user growth through our ongoing constant ecosystem first strategy. Research and development expenses increased RMB183 million from RMB166.5 million in the same period of 2022. The increase was primarily attributable to the increase in the salaries and the welfare of research and the development personnel, as well as the increased expenditures Zhihu's large language model training for this year's largest technology upgrades. Our large language model will gradually serve a broader user base in the Zhihu community going forward. General and administrative expenses decreased by 67.7% to RMB100.4 million from RMB310.6 million in the same period of 2022, primarily due to the lower share-based compensation expenses recognized and the decrease in professional service fees. Benefiting from our ongoing operations, efficiency improvements and cost control strategy, we greatly narrowed our net loss in Q1. Our GAAP net loss in the quarter was RMB179 million narrowing by 70.9% year-over-year. Our adjusted net loss on a non-GAAP basis, which primarily excludes share-based compensation expenses and amortization of intangible assets resulting from business acquisition, was RMB120.2 million for the first quarter, down by 67.3% from the same period of last year, with an adjusted net loss margin of 12.1%. In this quarter we generated RMB59.9 million operating cash flow marking the first time we have achieved positive operating cash flow since our IPO. This milestone demonstrates Zhihu's revenue diversification and business model and generative positive cash flow from its operations and represents an additional step towards becoming a profitable company. Now moving to our balance sheet. As of March 31, 2023, the company had cash and cash equivalents, term deposits and short-term investments of approximately RMB6,258 million compared with RMB6,262 million as of December 31, 2022. Also, as of March 31, 2023, we have repurchased approximately 6.9 million Class A ordinary shares at an aggregate price of US$17.8 million. This concludes my prepared remarks on our financial performance for the quarter. Let's turn the call over to the operator for the Q&A section. Thank you.