foo.c: In function 'main':
foo.c:6:10: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  int n1; scanf("%d",&n1);
          ^~~~~~~~~~~~~~~
foo.c:7:10: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  int n2; scanf("%d",&n2);
          ^~~~~~~~~~~~~~~
foo.c:10:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&a[i]); 
   ^~~~~~~~~~~~~~~~~
foo.c:14:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&b[i]); 
   ^~~~~~~~~~~~~~~~~

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