/* utilizzo es.5 */
#include <stdio.h>
#include <stdlib.h>

#define ZERO 0
#define TOP 1000

int main()

{
  int x = 0;
  int y = 0;
  int a, b, c;

  a = ZERO - abs(x);
  printf("a = %d", a);

  b = TOP - abs(y);
  printf("\nb = %d", b);

  c = a*b;
  printf("\nc = %d", c);

  return 0
}