View Compilation Error

0_0_30362688_14528.cpp: In function 'int main()':
0_0_30362688_14528.cpp:24:3: error: 'it' was not declared in this scope
   it z=strlen(a);
   ^
0_0_30362688_14528.cpp:25:17: error: 'z' was not declared in this scope
   for(int i=0;i<z;i++){
                 ^
0_0_30362688_14528.cpp:56:9: error: 'z' was not declared in this scope
   ans+=(z+1)%2;
         ^