/in/foo.cc: In function 'int main()':
/in/foo.cc:23:6: error: 'a' was not declared in this scope
  f(n,a,b,c);
      ^
/in/foo.cc:23:8: error: 'b' was not declared in this scope
  f(n,a,b,c);
        ^
/in/foo.cc:23:10: error: 'c' was not declared in this scope
  f(n,a,b,c);
          ^