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U. S. GOVERNMENT SECURITIES (Tables) | 12 Months Ended
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Jan. 31, 2022
Schedule of U.S. government securities classified as held-to-maturity | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | 2022 | ​ | 2021 |
​ | ​ | Carrying | ​ |  | ​ | ​ | Carrying | ​ |  | ​ |
​ |  | Value |  | Fair Value |  | Value |  | Fair Value |
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
Due within one year | ​ | $ | — | ​ | $ | — | ​ | $ | 9,906,669 | ​ | $ | 9,906,847 | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
Due after one year | ​ |  | — | ​ |  | — | ​ |  | — | ​ |  | — | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | $ | — | ​ | $ | — | ​ | $ | 9,906,669 | ​ | $ | 9,906,847 | ​

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- Definition Tabular disclosure of maturities of an entity's investments as well as any other information pertinent to the investments. + References No definition available. + Details
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Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
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