#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <stack>
#include <queue>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <ctime>

using namespace std;

typedef long long ll;
typedef unsigned long long ull;

static const double EPS = 1e-8;
static const double PI = 4.0 * atan(1.0);
static const double PI2 = 8.0 * atan(1.0);

#define REP(i,n)	for(int i=0;i<(int)n;++i)
#define ALL(c)		(c).begin(),(c).end()
#define CLEAR(v)	memset(v,0,sizeof(v))
#define MP(a,b)		make_pair((a),(b))
#define ABS(a)		((a)>0?(a):-(a))
#define FOR(i,s,n)	for(int i=s;i<(int)n;++i)

int V[4];
int dp[62];

int solve(int a, int b, int c) {
	int r[3] = { a, b, c };
	FOR(i, 1, 31) dp[i] = 200;
	dp[0] = 0;
	REP(i, 30) REP(j, 3) dp[i + r[j]] = min(dp[i + r[j]], dp[i] + 1);
	return dp[V[0]] + dp[V[1]] + dp[V[2]] + dp[V[3]];
}

int main(int argc, char **argv) {
	REP(i, 4) cin >> V[i];
	int res = 200;
	FOR(a, 1, 31) FOR(b, 1, 31) FOR(c, 1, 31) res = min(res, solve(a, b, c));
	cout << res << endl;
	return 0;
}