#include <iostream>
#include <string>
#include <cstdlib>
#include <cmath>
#include <vector>
#include <unordered_map>
#include <map>
#include <set>
#include <algorithm>
#include <queue>
#include <stack>
#include <functional>
#include <bitset>
#include <assert.h>
#include <unordered_map>
#include <fstream>
#include <ctime>
#include <complex>
using namespace std;
typedef long long ll;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<char> vc;
typedef vector<string> vs;
typedef vector<bool> vb;
typedef vector<double> vd;
typedef pair<ll,ll> P;
typedef pair<int,int> pii;
typedef vector<P> vpl;
typedef tuple<ll,ll,ll> tapu;
#define rep(i,n) for(int i=0; i<(n); i++)
#define REP(i,a,b) for(int i=(a); i<(b); i++)
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
const int inf = 1<<30;
const ll linf = 1LL<<62;
const int MAX = 1020000;
ll dy[8] = {1,-1,0,0,1,-1,1,-1};
ll dx[8] = {0,0,1,-1,1,-1,-1,1};
const double pi = acos(-1);
const double eps = 1e-7;
template<typename T1,typename T2> inline bool chmin(T1 &a,T2 b){
	if(a>b){
		a = b; return true;
	}
	else return false;
}
template<typename T1,typename T2> inline bool chmax(T1 &a,T2 b){
	if(a<b){
		a = b; return true;
	}
	else return false;
}
template<typename T> inline void print(T &a){
    rep(i,a.size()) cout << a[i] << " ";
    cout << "\n";
}
template<typename T1,typename T2> inline void print2(T1 a, T2 b){cout << a << " " << b << "\n";}
template<typename T1,typename T2,typename T3> inline void print3(T1 a, T2 b, T3 c){
	cout << a << " " << b << " " << c << "\n";
}
ll pcount(ll x) {return __builtin_popcountll(x);}
//const int mod = 1e9 + 7;
const int mod = 998244353;

ll f(vl w, ll t){
	ll res = t;
	w[0] -= t; w[4] -= t;
	rep(i,5){
		res += max(w[i],0LL);
		if(i<4) w[i+1] -= max(w[i],0LL);
	}
	return res;
}

int main(){
	int n = 5;
	vl v(n); rep(i,n) cin >> v[i];
	ll ok = 0, ng = 3000000000000000;
	while(ng-ok > 1){
		ll mid = (ok+ng) / 2;
		vl u(5);
		rep(i,n) u[i] = max(0LL,mid-v[i]);
		ll l = -1, r = 1000000000000001;
		while(r-l > 2){
			ll ml = (l*2 + r) / 3;
			ll mr = (l + r*2) / 3;
			if(f(u,ml) > f(u,mr)) l = ml;
			else r = mr;
		}
		//print3(mid,r-1,f(u,r-1));
		if(f(u,r-1) > mid) ng = mid;
		else ok = mid;
	}
	cout << ok << endl;
}