/in/foo.cc:1:1: error: 'e' does not name a type
    1 | e <iostream>
      | ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:5:8: error: 'cin' was not declared in this scope
    5 |  while(cin>>n){
      |        ^~~
/in/foo.cc:6:3: error: 'cout' was not declared in this scope
    6 |   cout<<n*n<<endl;
      |   ^~~~
/in/foo.cc:6:14: error: 'endl' was not declared in this scope
    6 |   cout<<n*n<<endl;
      |              ^~~~