/in/foo.cc: In function 'int main()':
/in/foo.cc:5:5: error: 'cin' was not declared in this scope
     cin>>n;
     ^~~
/in/foo.cc:6:5: error: 'cout' was not declared in this scope
     cout<<n*n-1;
     ^~~~
/in/foo.cc:6:16: error: expected '}' at end of input
     cout<<n*n-1;
                ^