foo.c:3:6: warning: return type of 'main' is not 'int' [-Wmain]
    3 | void main()
      |      ^~~~
foo.c: In function 'Merge':
foo.c:24:22: warning: left-hand operand of comma expression has no effect [-Wunused-value]
   24 |  for(i=n1,j=0;i<n1+n2,j<n2;i++,j++)
      |                      ^
foo.c: In function 'main':
foo.c:9:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
    9 |  scanf("%d %d %d",&n1,&n2,&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:13:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   13 |   scanf("%d",&a2[i]);
      |   ^~~~~~~~~~~~~~~~~~
foo.c:15:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   15 |   scanf("%d",&a3[i]);
      |   ^~~~~~~~~~~~~~~~~~

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