This problem is in Contest(s) below:
Contest 1019:2020DLOI
Contest 1201:1113-进制转换专题练习
Contest 1259:2020DLOI
Contest 1145:0214练习-1161-1167
Contest 1112:少年宫4班(六)0513
Contest 1113:少年宫8班(六)0513