#include <bits/stdc++.h>
using namespace std;
#define file ""
#define mp make_pair
#define fi first
#define se second
#define all(x) x.begin(), x.end()
#define getbit(x, i) (((x) >> (i)) & 1)
#define bit(x) (1LL << (x))
#define popcount __builtin_popcountll
mt19937_64 rd(chrono::steady_clock::now().time_since_epoch().count());
int rand(int l, int r) {
return l + rd() % (r - l + 1);
}
const int N = 300 + 5;
const int mod = (int)1e9 + 7; // 998244353;
const int lg = 25; // lg + 1
const int oo = 1e9;
const long long ooo = 1e18;
template<class X, class Y> bool mini(X &a, Y b) {
return a > b ? (a = b, true) : false;
}
template<class X, class Y> bool maxi(X &a, Y b) {
return a < b ? (a = b, true) : false;
}
void add(int &a, int b) {
a += b;
if (a >= mod) a -= mod;
if (a < 0) a += mod;
}
int n;
int a[N];
int f[N][N][N];
int calc(int i, int h1, int h2) {
if (i > n) {
return min(h1, h2) * 5 + (max(h1, h2) - min(h1, h2)) * 3;
}
int &res = f[i][h1][h2];
if (res != -1) return res;
res = oo;
int mn = min({a[i], h1, h2});
if (mn == h2) {
mini(res, calc(i + 1, a[i] - mn, h1 - mn) + mn * 7);
}
if (h1 && h2) {
mini(res, calc(i, h1 - 1, h2 - 1) + 5);
}
if (h2) {
mini(res, calc(i, h1, h2 - 1) + 3);
}
return res;
}
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
// freopen(file".inp", "r", stdin);
// freopen(file".out", "w", stdout);
cin >> n;
for (int i = 1; i <= n; ++i)
cin >> a[i];
memset(f, -1, sizeof f);
cout << calc(3, a[2], a[1]);
return 0;
}
/*
*/
