foo.cc: In function 'int main()':
foo.cc:63:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   63 |     scanf( "%d%d", &n, &k );
      |     ~~~~~^~~~~~~~~~~~~~~~~~
foo.cc:69:27: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   69 |             char ch; scanf( "%c", &ch );
      |                      ~~~~~^~~~~~~~~~~~~
foo.cc:78:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   78 |         int x, y; scanf( "%d%d", &x, &y );
      |                   ~~~~~^~~~~~~~~~~~~~~~~~

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