View Compilation Error

0_0_30135507_30858.cpp: In function 'int main()':
0_0_30135507_30858.cpp:57:9: error: 'cout' was not declared in this scope
         cout<<ans<<endl;
         ^
0_0_30135507_30858.cpp:57:20: error: 'endl' was not declared in this scope
         cout<<ans<<endl;
                    ^