foo.c: In function 'input':
foo.c:4:18: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
    4 |  for(i=0;i<n;i++)scanf("%d ",&a[i]);}
      |                  ^~~~~~~~~~~~~~~~~~
foo.c: In function 'main':
foo.c:10:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   10 |  scanf("%d",&n);
      |  ^~~~~~~~~~~~~~

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