foo.c: In function 'main':
foo.c:12:6: error: 'i' undeclared (first use in this function)
  for(i=0;i<n2;i++)
      ^
foo.c:12:6: note: each undeclared identifier is reported only once for each function it appears in
foo.c: In function 'FindiSecondMax':
foo.c:19:5: warning: unused variable 'x' [-Wunused-variable]
 int x;
     ^
foo.c: In function 'main':
foo.c:7:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&n1,&n2);
  ^~~~~~~~~~~~~~~~~~~~~
foo.c:9:5: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d",&a[i]);
     ^~~~~~~~~~~~~~~~~

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