foo.cc: In function 'void init()':
foo.cc:26:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   26 |  scanf("%d%d",&n,&m);
      |  ~~~~~^~~~~~~~~~~~~~
foo.cc:29:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   29 |   scanf("%d%d%d%d",&x,&y,&c,&d);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
foo.cc:32:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   32 |     scanf("%d%d%d",&s,&t,&k);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~

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