foo.c:36:6: warning: return type of 'main' is not 'int' [-Wmain]
   36 | void main()
      |      ^~~~
foo.c: In function 'main':
foo.c:39:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   39 |  scanf("%d%d%d",&n1,&n2,&n3);
      |  ^~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.c:43:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   43 |   scanf("%d",&a1[i]);
      |   ^~~~~~~~~~~~~~~~~~
foo.c:47:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   47 |   scanf("%d",&a2[i]);
      |   ^~~~~~~~~~~~~~~~~~
foo.c:51:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   51 |   scanf("%d",&a3[i]);
      |   ^~~~~~~~~~~~~~~~~~

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