#include <bits/stdc++.h>
#define ll long long
using namespace std;
const int INF = 1e9;
const int MOD = 1e9 + 7;
int n, v[302], dp[302][202][202];
int main ()
{
ios_base::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
cin >> n;
for (int i = 1; i <= n; i++)
cin >> v[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] = INF;
for (int i = 0; i <= v[1]; i++)
dp[2][v[2]][i] = dp[1][i][0] = 3 * (v[1] - i);
for (int i = 2; i <= n; i++) {
for (int j = v[i]; j >= 0; j--)
for (int k = 0; k <= v[i - 1]; k++) {
dp[i][j][k] = min(dp[i][j + 1][k] + 3, dp[i][j][k]);
dp[i][j][k] = min(dp[i][j + 1][k + 1] + 5, dp[i][j][k]);
}
for (int j = 0; j <= min(v[i], min(v[i + 1], v[i - 1])); j++)
for (int k = v[i + 1]; k >= j; k--)
dp[i + 1][v[i + 1] - j][k - j] = min(dp[i + 1][v[i + 1] - j][k - j], dp[i][k][j] + 7 * j);
}
cout << dp[n][0][0];
return 0;
}
