#include <iostream>
#include <sstream>
#include <math.h>
#include <vector>
#include <array>
#include <algorithm>
#include <queue>
#include <numeric>
#include <map>
#include <set>
#include <bitset>

using namespace std;
//#define int long long
#define FOR(i, a, b) for(int i=(a);i<(b);i++)
#define RFOR(i, a, b) for(int i=(b-1);i>=(a);i--)
#define REP(i, n) for(int i=0; i<(n); i++)
#define RREP(i, n) for(int i=(n-1); i>=0; i--)
#define ALL(a) (a).begin(),(a).end()
#define UNIQUE_SORT(l) sort(ALL(l)); l.erase(unique(ALL(l)), l.end());
#define CONTAIN(a, b) find(ALL(a), (b)) != (a).end()
#define SUM(a) accumulate(ALL(a), 0)
#define array2(type, x, y) array<array<type, y>, x>
#define vector2(type) vector<vector<type> >
#define out(...) printf(__VA_ARGS__)

/*================================*/

vector<int> V(4, 0);
int INF = 1 << 15;

signed main()
{
    REP(i,4) cin >> V[i];
    // 3枚の板を用意
    int minc = INF;
    FOR(i,1,31) FOR(j,i,31) FOR(k,j,31) {
        // DP
        int dp[100];
        REP(i,31) dp[i] = INF;
        dp[0] = 0;
        int L[3] = {i, j, k};
        REP(l,3) {
            int n = L[l];
            REP(m,31) {
                dp[m + n] = min(dp[m+n], dp[m] + 1);
            }
        }
        int cnt = 0;
        REP(m,4) cnt += dp[V[m]];
        minc = min(minc, cnt);
    }

    cout << minc << endl;

    return 0;
}