/in/foo.cc: In function 'int main()':
/in/foo.cc:3:3: error: 'int64' was not declared in this scope
   int64 x,y;
   ^~~~~
/in/foo.cc:4:3: error: 'cin' was not declared in this scope
   cin >> x >> y;
   ^~~
/in/foo.cc:4:3: note: suggested alternative:
In file included from /in/foo.cc:1:0:
/usr/include/c++/6/iostream:60:18: note:   'std::cin'
   extern istream cin;  /// Linked to standard input
                  ^~~
/in/foo.cc:4:10: error: 'x' was not declared in this scope
   cin >> x >> y;
          ^
/in/foo.cc:4:15: error: 'y' was not declared in this scope
   cin >> x >> y;
               ^
/in/foo.cc:5:3: error: 'cout' was not declared in this scope
   cout << x*y+x+y;
   ^~~~
/in/foo.cc:5:3: note: suggested alternative:
In file included from /in/foo.cc:1:0:
/usr/include/c++/6/iostream:61:18: note:   'std::cout'
   extern ostream cout;  /// Linked to standard output
                  ^~~~