foo.cc: In function 'int main()':
foo.cc:18:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   18 |         scanf("%d", &n);
      |         ~~~~~^~~~~~~~~~
foo.cc:20:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   20 |             scanf("%d", a + i);
      |             ~~~~~^~~~~~~~~~~~~
foo.cc:21:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   21 |         scanf("%d", &m);
      |         ~~~~~^~~~~~~~~~
foo.cc:23:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   23 |             scanf("%d", b + i);
      |             ~~~~~^~~~~~~~~~~~~

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