foo.c: In function 'fun':
foo.c:7:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
    7 |   scanf("%d",&a[i]);
      |   ^~~~~~~~~~~~~~~~~
foo.c: In function 'main':
foo.c:42:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   42 |  scanf("%d %d %d",&n1,&n2,&n3);
      |  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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