foo.cc: In function 'int main()':
foo.cc:10:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   10 |     scanf("%d %d", &m, &n);
      |     ~~~~~^~~~~~~~~~~~~~~~~
foo.cc:13:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   13 |         scanf("%d", &a[i]);
      |         ~~~~~^~~~~~~~~~~~~
foo.cc:17:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   17 |         scanf("%d", &b[i]);
      |         ~~~~~^~~~~~~~~~~~~

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