View Compilation Error

0_0_38327651_22174.cpp: In function 'int main()':
0_0_38327651_22174.cpp:20:5: error: 'cin' was not declared in this scope
     cin>>n>>m;
     ^
0_0_38327651_22174.cpp:47:5: error: 'cout' was not declared in this scope
     cout<<ans;
     ^