foo.cc: In function 'int main()':
foo.cc:8:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    8 |     scanf("%d", &n);
      |     ~~~~~^~~~~~~~~~
foo.cc:10:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   10 |         scanf("%d %d %d %d", &a[i], &b[i], &g[i], &k[i]);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.cc:11:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   11 |     scanf("%d %d", &x, &y);
      |     ~~~~~^~~~~~~~~~~~~~~~~

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