foo.cc:1:1: error: 'include' does not name a type
 include <bits/stdc++.h>
 ^~~~~~~
foo.cc: In function 'int main()':
foo.cc:6:2: error: 'cin' was not declared in this scope
  cin >> a >> b;
  ^~~
foo.cc:6:2: note: suggested alternative: 'main'
  cin >> a >> b;
  ^~~
  main
foo.cc:7:2: error: 'cout' was not declared in this scope
  cout << b << " " << a;
  ^~~~