you give string length 5 call time represent current time digital clock format hhmm the early possible time 0000 late possible time 2359in string time digit represent symbol unknown replace digit 0 9Return integer answer number valid clock time create replace digit 0 9 example 1input time 500output 2explanation we replace 0 1 produce 0500 1500 note replace 2 time 2500 invalid in total choicesexample 2input time 00output 100explanation each replace digit 0 9 100 total choicesexample 3input time output 1440explanation there 24 possible choice hour 60 possible choice minute in total 24 60 1440 choice Constraintstime valid string length 5 format hhmm00 hh 2300 mm 59some digit replace need replace digit 0 9