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5 Risk management (Details 1) | Dec. 31, 2020 R$ / $ R$ / ¥ | Dec. 31, 2019 R$ / $ R$ / ¥
--- | --- | ---
Yen |  |
Summary of risk management [Line Items] |  |
Exchange rate | R$ / ¥ | 0.05043 | 0.03715
Exchange rate variation | 28.90% |
USD |  |
Summary of risk management [Line Items] |  |
Exchange rate | R$ / $ | 5.1967 | 4.0307
Exchange rate variation | 35.70% |

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