#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(i, n) for(ll i = 0, i##_len = (n); i < i##_len; i++)
#define reps(i, s, n) for(ll i = (s), i##_len = (n); i < i##_len; i++)
#define rrep(i, n) for(ll i = (n) - 1; i >= 0; i--)
#define rreps(i, e, n) for(ll i = (n) - 1; i >= (e); i--)
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define sz(x) ((ll)(x).size())
#define len(x) ((ll)(x).length())
#define endl "\n"

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    // ifstream in("input.txt");
    // cin.rdbuf(in.rdbuf());
    const ll inf = LONG_LONG_MAX / 4 - 1;
    ll v0, v1, v2, v3;
    cin >> v0 >> v1 >> v2 >> v3;
    ll mv = v0;
    mv = max(mv, v1);
    mv = max(mv, v2);
    mv = max(mv, v3);
    ll ans = LONG_LONG_MAX;
    reps(a, 1, 31) {
        reps(b, a + 1, 31) {
            reps(c, b + 1, 31) {
                vector<ll> dp(mv + 1, inf);
                dp[0] = 0;
                reps(i, a, mv + 1) {
                    if (dp[i - a] == inf) continue;
                    dp[i] = min(dp[i], dp[i - a] + 1);
                }
                reps(i, b, mv + 1) {
                    if (dp[i - b] == inf) continue;
                    dp[i] = min(dp[i], dp[i - b] + 1);
                }
                reps(i, c, mv + 1) {
                    if (dp[i - c] == inf) continue;
                    dp[i] = min(dp[i], dp[i - c] + 1);
                }
                ans = min(ans, dp[v0] + dp[v1] + dp[v2] + dp[v3]);
            }
        }
    }
    cout << ans << endl;
    return 0;
}