// yukicoder: No.325 マンハッタン距離2
// 2019.7.7 bal4u

#include <stdio.h>
#include <stdlib.h>

typedef long long ll;
#define ABS(x)  ((x)>=0?(x):-(x))
#define MIN(x,y) ((x)<=(y)?(x):(y))

ll sa; int sx, sy;
void calc(int x, int y, int d) {
	ll t = MIN(x+y, d);
	sa = (t+1)*(t+2)/2 - 1, sx = sy = t;
	if (x < t) sa -= (t-x)*(t-x+1)/2, sx = x;
	if (y < t) sa -= (t-y)*(t-y+1)/2, sy = y;
}

int main()
{
	int x1, y1, x2, y2, d;
	ll ans;

	scanf("%d%d%d%d%d", &x1, &y1, &x2, &y2, &d);
	if ((ll)x1*x2 > 0) d -= MIN(ABS(x1),ABS(x2)), x2 = x2-x1, x1 = 0;
	if ((ll)y1*y2 > 0) d -= MIN(ABS(y1),ABS(y2)), y2 = y2-y1, y1 = 0;

	ans = 1;
	if (d < 0) ans = 0;
	else if (d > 0) {
		calc( x2,  y2, d), ans += sa;
		calc(-x1,  y2, d), ans += sa - sy;
		calc(-x1, -y1, d), ans += sa - sx;
		calc( x2, -y1, d), ans += sa - (sx+sy);
	}
	printf("%lld\n", ans);
	return 0;
}