foo.cc: In function 'int main()':
foo.cc:19:6: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   19 | scanf("%d", &n);
      | ~~~~~^~~~~~~~~~
foo.cc:34:7: warning: ignoring return value of 'int system(const char*)', declared with attribute warn_unused_result [-Wunused-result]
   34 | system("pause");
      | ~~~~~~^~~~~~~~~

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