CASH, CASH EQUIVALENTS AND SHORT-TERM INVESTMENTS (Details) - Held-to-maturity Securities	6 Months Ended	12 Months Ended
Jul. 31, 2021	Jan. 31, 2021
Cash and Cash Equivalents
Maturity period	1 year	1 year
Weighted average annual interest rates of CDs (as a percent)	0.20%	0.20%

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