View Compilation Error

0_0_35952204_19853.cpp: In function 'int main()':
0_0_35952204_19853.cpp:15:5: error: 'ans' was not declared in this scope
     ans=a;
     ^
0_0_35952204_19853.cpp:19:10: error: 'ans' was not declared in this scope
    cout<<ans<<endl;
          ^