What is the output(#35)?

Question

#include <stdio.h>

int main()

{

int *ptr1, *ptr2, arr[] = {1, 2, 3, 4, 5};

ptrl = &arr[0];

ptr2 = &arr[3];

printf("%d\n", ptr1[ptr2 - ptrl]);

return 0;

}

 

References: C From Theory