foo.c: In function 'in':
foo.c:6:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&a[i]);
   ^~~~~~~~~~~~~~~~~
foo.c:8:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
foo.c: In function 'SetInter':
foo.c:16:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
foo.c: In function 'main':
foo.c:20:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d %d",&n1,&n2,&n3);
  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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