View Compilation Error

0_0_36726760_15688.cpp:13:9: error: conflicting declaration 'int a [31]'
 int a[31],b[31],ans=0; 
         ^
0_0_36726760_15688.cpp:5:8: note: previous declaration as 'std::string a'
 string a,b;
        ^
0_0_36726760_15688.cpp:13:15: error: conflicting declaration 'int b [31]'
 int a[31],b[31],ans=0; 
               ^
0_0_36726760_15688.cpp:5:10: note: previous declaration as 'std::string b'
 string a,b;
          ^