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Risks and Concentration (Details) ¥ in Thousands, $ in Thousands | Jun. 30, 2021 CNY (¥) | Dec. 31, 2020 CNY (¥) | Dec. 31, 2020 USD ($) | Jun. 30, 2020 | Dec. 31, 2019 CNY (¥)
--- | --- | --- | --- | --- | ---
Risks and Concentration (Details) [Line Items] |  |  |  |  |
Cash and cash equivalents | ¥ 175,391 |  | $ 123,385 |  |
Short term borrowings | ¥ 1,000 | ¥ 1,000 |  |  | ¥ 28,788
Two Suppliers [Member] |  |  |  |  |
Risks and Concentration (Details) [Line Items] |  |  |  |  |
Total cost of revenue, percentage | 10.00% |  |  |  |
One Customers [Member] |  |  |  |  |
Risks and Concentration (Details) [Line Items] |  |  |  |  |
Total cost of revenue, percentage |  |  |  | 10.00% |
Three Customers [Member] |  |  |  |  |
Risks and Concentration (Details) [Line Items] |  |  |  |  |
Total cost of revenue, percentage | 10.00% |  |  |  |

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