// Given an array A and the address of element A[x], find the value of  x
#include <stdio.h>
#define TESTVALUE 5
int main(void)
{
  int x=TESTVALUE;
  int A[]={0,1,2,3,4,5,6,7,8,9};
  printf("x=%d\n", (&A[x] - &A[0]));
  return 0;
}