foo.cc: In function 'int main()':
foo.cc:32:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d",&n1,&n2);
  ~~~~~^~~~~~~~~~~~~~~~~
foo.cc:34:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&a[i]);
   ~~~~~^~~~~~~~~~~~
foo.cc:36:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&b[i]);
   ~~~~~^~~~~~~~~~~~

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