#include<iostream>
#include<vector>
#include<algorithm>
#include<functional>
#include<set>
#include<map>
#include<string>
#include<iomanip>
#include<cmath>
#include<stack>
#include<tuple>

int main()
{
	int V[4] = {};
	int min = 0;
	for (auto& v : V)
	{
		std::cin >> v;
		min += v;
	}
	for (auto A = 1; A <= 30; ++A)
	{
		for (auto B = A + 1; B <= 30; ++B)
		{
			for (auto C = B + 1; C <= 30; ++C)
			{
				int dp[31] = {};
				for (auto& d : dp)
				{
					d = 120;
				}
				dp[0] = 0;
				for (int i = 0; i < 30; ++i)
				{
					if (i + A <= 30)
					{
						dp[i + A] = std::min(dp[i + A], dp[i] + 1);
					}
					if (i + B <= 30)
					{
						dp[i + B] = std::min(dp[i + B], dp[i] + 1);
					}
					if (i + C <= 30)
					{
						dp[i + C] = std::min(dp[i + C], dp[i] + 1);
					}
				}
				int s = 0;
				for (auto v : V)
				{
					s += dp[v];
				}
				min = std::min(min, s);
			}
		}
	}
	std::cout << min << std::endl;
}