foo.c: In function 'main':
foo.c:6:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
    6 |  scanf("%d",&n1);
      |  ^~~~~~~~~~~~~~~
foo.c:7:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
    7 |  scanf("%d",&n2);
      |  ^~~~~~~~~~~~~~~
foo.c:8:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
    8 |  scanf("%d",&n3);
      |  ^~~~~~~~~~~~~~~
foo.c:11:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   11 |   scanf("%d",&a1[i]);
      |   ^~~~~~~~~~~~~~~~~~
foo.c:15:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   15 |   scanf("%d",&a2[j]);
      |   ^~~~~~~~~~~~~~~~~~
foo.c:19:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   19 |   scanf("%d",&a3[l]);
      |   ^~~~~~~~~~~~~~~~~~

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