evaluate value arithmetic expression Reverse Polish NotationValid operator each operand integer expressionnote division integer truncate zeroIt guarantee give RPN expression valid that mean expression evaluate result division zero operation Example 1input token 213output 9explanation 2 1 3 9example 2input token 4135output 6explanation 4 13 5 6example 3input tokens 1069311175output 22explanation 10 6 9 3 11 17 5 10 6 12 11 17 5 10 6 132 17 5 10 0 17 5 0 17 5 17 5 22 Constraints1 tokenslength 104tokensi operator integer range 200 200