View Compilation Error

0_0_34037360_19397.cpp:32:10: error: '::main' must return 'int'
 int main()
          ^
0_0_34037360_19397.cpp: In function 'int main()':
0_0_34037360_19397.cpp:40:9: error: 'ans' was not declared in this scope
         ans=0;
         ^