/in/foo.cc:3:1: error: 'itn' does not name a type
 itn a,b;
 ^~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:6:10: error: 'a' was not declared in this scope
     cin>>a>>b;
          ^
/in/foo.cc:6:13: error: 'b' was not declared in this scope
     cin>>a>>b;
             ^