/in/foo.cc: In function 'int main()':
/in/foo.cc:37:6: warning: variable 'fg' set but not used [-Wunused-but-set-variable]
  int fg;
      ^~
/in/foo.cc:73:18: warning: 'ans' may be used uninitialized in this function [-Wmaybe-uninitialized]
  printf("%d",ans);
                  ^