#include<bits/stdc++.h>
#define taskname "B"
using namespace std;
const int lim = 305;
const int LIM = 205;
const int INF = 1e9;
int n, a[lim], f[lim][LIM][LIM];
int dp(int p, int a1, int a2){
if(p < 1 || a1 < 0 || a2 < 0){
return INF;
}
int& ans = f[p][a1][a2];
if(ans != -1){
return ans;
}
if(p == 1){
vector<int>b = {a[p], a1, a2};
int x = min({b[0], b[1], b[2]});
for(int i = 0; i < 3; i++){
b[i] -= x;
}
if(b[0] > 0 && b[1] > 0){
return ans = x * 7 + (min(b[0], b[1]) << 1) + max(b[0], b[1]) * 3;
}
if(b[1] > 0 && b[2] > 0){
return ans = x * 7 + (min(b[1], b[2]) << 1) + max(b[1], b[2]) * 3;
}
return ans = x * 7 + (b[0] + b[1] + b[2]) * 3;
}
if(a2 == 0){
return ans = dp(p - 1, a[p], a1);
}
return ans = min({dp(p, a1, a2 - 1) + 3, dp(p, a1 - 1, a2 - 1) + 5, dp(p - 1, a[p] - a2, a1 - a2) + 7 * a2});
}
int main(){
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
if(fopen(taskname".inp", "r")){
freopen(taskname".inp", "r", stdin);
}
cin >> n;
for(int i = 1; i <= n; i++){
cin >> a[i];
}
if(n == 1){
return cout << a[1] * 3, 0;
}
if(n == 2){
return cout << (min(a[1], a[2]) << 1) + max(a[1], a[2]) * 3, 0;
}
memset(f, -1, sizeof(f));
cout << dp(n - 2, a[n - 1], a[n]);
}
