/in/foo.cc:4:1: error: 'longlong' does not name a type
    4 | longlong n,m;
      | ^~~~~~~~
cc1plus: error: '::main' must return 'int'
/in/foo.cc: In function 'int main()':
/in/foo.cc:7:10: error: 'n' was not declared in this scope; did you mean 'yn'?
    7 |     cin>>n>>m;
      |          ^
      |          yn
/in/foo.cc:7:13: error: 'm' was not declared in this scope; did you mean 'tm'?
    7 |     cin>>n>>m;
      |             ^
      |             tm