Long-term debts - Outstanding balances of long-term debts (Details)	Dec. 31, 2022 CNY (¥)
Debt Disclosure [Abstract]
2023	¥ 280,000
2024	420,000
2025	560,000
2026	700,000
2027	840,000
Thereafter	14,153,316
Total	¥ 16,953,316

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Amount, excluding unamortized premium (discount) and debt issuance cost, of long-term debt. Excludes lease obligation.

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing after fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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