V = list(map(int, input().split()))

mi = float('inf')

for a in range(1, 29):
    for b in range(a + 1, 30):
        for c in range(b + 1, 31):
            dp = [float('inf') for i in range(31)]
            dp[0] = 0
            for i in range(1, 31):
                if i - a >= 0:
                    dp[i] = min(dp[i], dp[i - a] + 1)
                if i - b >= 0:
                    dp[i] = min(dp[i], dp[i - b] + 1)
                if i - c >= 0:
                    dp[i] = min(dp[i], dp[i - c] + 1)
            mi = min(dp[V[0]] + dp[V[1]] + dp[V[2]] + dp[V[3]], mi)
            
print(mi)