foo.cc: In function 'int main()':
foo.cc:9:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    9 |  scanf("%d", &n);
      |  ~~~~~^~~~~~~~~~
foo.cc:12:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   12 |   scanf("%d", &data[i]);
      |   ~~~~~^~~~~~~~~~~~~~~~
foo.cc:21:8: warning: ignoring return value of 'int system(const char*)', declared with attribute warn_unused_result [-Wunused-result]
   21 |  system("pause");
      |  ~~~~~~^~~~~~~~~

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