// yukicoder: 27 板の準備
// 2019.9.3 bal4u

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

int v[4];
int dp[33];

int cmp(const void *u, const void *v) { return *(int *)u - *(int *)v; }
inline static void chmin(int *a, int b) { if (*a > b) *a = b; }

int check(int *a) {
	int i, j, s;
	memset(dp, 0x01, sizeof(dp)); dp[0] = 0;
	for (i = 1; i <= 3; i++) for (j = a[i]; j <= 30; j++) chmin(&dp[j], dp[j-a[i]]+1);
	s = 0; for (i = 0; i < 4; i++) s += dp[v[i]];
	return s;
}
		
int main()
{
	int i, t, a[4], ans;
	
	for (i = 0; i < 4; i++) scanf("%d", v+i);
	qsort(v, 4, sizeof(int), cmp);
	ans = 10000;
	for (a[1] = 1; a[1] <= v[0]; a[1]++)
		for (a[2] = a[1]+1; a[2] < v[3]; a[2]++)
			for (a[3] = a[2]+1; a[3] <= v[3]; a[3]++) {
				if ((t = check(a)) < ans) ans = t;
			}
	printf("%d\n", ans);
	return 0;
}