/in/foo.cc:1:2: error: invalid preprocessing directive #includ
 #includ<iostream>
  ^~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:7:2: error: 'cin' was not declared in this scope
  cin>>a>>c>>b;
  ^~~
/in/foo.cc:10:3: error: 'cout' was not declared in this scope
   cout<<a+b;
   ^~~~
/in/foo.cc:14:3: error: 'cout' was not declared in this scope
   cout<<a-b;
   ^~~~