/in/foo.cc: In function 'int main()':
/in/foo.cc:12:6: warning: unused variable 'a' [-Wunused-variable]
  int a, b, c;
      ^
/in/foo.cc:12:9: warning: unused variable 'b' [-Wunused-variable]
  int a, b, c;
         ^
/in/foo.cc:12:12: warning: unused variable 'c' [-Wunused-variable]
  int a, b, c;
            ^