foo.cc: In function 'int main()':
foo.cc:27:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   27 |  scanf("%d%d",&n1,&n2);
      |  ~~~~~^~~~~~~~~~~~~~~~
foo.cc:29:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   29 |   scanf("%d",&a[i]);
      |   ~~~~~^~~~~~~~~~~~

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