#include<bits/stdc++.h>
#define IOS ios_base::sync_with_stdio(false);cin.tie();cout.tie();
#define all(x) x.begin(), x.end()
#define lnl long long
#define pq priority_queue
#define eb emplace_back
#define lb lower_bound
#define ub upper_bound
#define pb push_back
#define pp pop_back
#define F first
#define S second
using namespace std;
int antiloop = 0;
int dp[301][201][201];
int a[301];
void solve () {
int n; cin >> n;
for (int i = 1; i <= n; i++) cin >> a[i];
for (int i = 1; i <= 300; i++)
for (int j = 0; j <= 200; j++)
for (int k = 0; k <= 200; k++)
dp[i][j][k] = 1e9;
for (int i = 0; i <= a[1]; i++) dp[2][a[1]-i][a[2]] = dp[1][0][a[1]-i] = i*3;
for (int i = 2; i <= n; i++) {
for (int j = a[i-1]; j >= 0; j--)
for (int k = a[i]; k >= 0; k--)
dp[i][j][k] = min(dp[i][j][k], dp[i][j][k+1]+3);
for (int j = a[i-1]; j >= 0; j--)
for (int k = a[i]; k >= 0; k--)
dp[i][j][k] = min(dp[i][j][k], dp[i][j+1][k+1]+5);
if (i != n) {
for (int j = min({a[i-1], a[i], a[i+1]}); j >= 0; j--)
for (int k = a[i]; k >= j; k--)
dp[i+1][k-j][a[i+1]-j] = min(dp[i+1][k-j][a[i+1]-j], dp[i][j][k] + j*7);
}
}
cout << dp[n][0][0];
}
int main() {IOS solve(); return 0;}
