# coding: utf-8
V = map(int, raw_input().split())
INF = int(1e9+7)
ans = INF
for a in range(1,31):
	for b in range(a,31):
		for c in range(b,31):
			dp = [INF for _ in range(31)]
			dp2 = [[0, 0 ,0], ]
			dp[0] = 0
			for i in range(1,31):
				at = INF if i - a < 0 else dp[i-a]
				bt = INF if i - b < 0 else dp[i-b]
				ct = INF if i - c < 0 else dp[i-c]
				dp[i] = min(at, bt, ct) + 1
			ans = min(ans, dp[V[0]]+dp[V[1]]+dp[V[2]]+dp[V[3]])

print ans