/in/foo.cc: In function 'void work()':
/in/foo.cc:56:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d",&sx[i],&sy[i]);
                              ^
/in/foo.cc:66:16: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&k);
                ^
/in/foo.cc:68:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d",&x,&y);
                      ^