#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;
typedef long long ll;

const ll INF = (1LL << 62) - 1;

bool solve(vector<ll> v, ll target) {
    for (auto &x:v)x -= target;

    int maxPos = 0;
    for (int i = 0; i < 5; i++) {
        if (v[maxPos] < v[i]) maxPos = i;
    }

    ll addCount = 0;
    if (v[maxPos] <= -2) {
        addCount += (-v[maxPos]) / 2 * 5;
        for (auto &x:v)x += addCount / 5;
    }

    ll left = 0;
    vector<ll> tmp = v;
    for (int i = 0; i < 5; i++) {
        int here = (maxPos + i) % 5;
        if (tmp[here] < 0) {
            ll add = -tmp[here];
            left += add, tmp[here] += add, tmp[(here + 1) % 5] += add;
        }
    }
    ll right = 0;
    tmp = v;
    for (int i = 0; i < 5; i++) {
        int here = (maxPos - i + 5) % 5;
        if (tmp[here] < 0) {
            ll add = -tmp[here];
            right += add, tmp[here] += add, tmp[(here - 1 + 5) % 5] += add;
        }
    }

    addCount += min(left, right);

    return addCount <= target;
}

int main() {
    vector<ll> v(5);
    for (int i = 0; i < 5; i++)cin >> v[i];

    ll ok = 0, ng = 1e16;
    while (ng - ok > 1) {
        ll mid = (ng + ok) / 2;
        if (solve(v, mid))ok = mid;
        else ng = mid;
    }

    cout << ok << endl;
    return 0;
}