/in/foo.cc: In function 'int main()':
/in/foo.cc:39:21: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&K,&n);
                     ^
/in/foo.cc:43:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d%d",&x,&z,&op);
                            ^