/in/foo.cc: In function 'void work()':
/in/foo.cc:56:34: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%lld%lld",&sx[i],&sy[i]);
                                  ^
/in/foo.cc:66:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%lld",&k);
                  ^
/in/foo.cc:68:26: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%lld%lld",&x,&y);
                          ^