#include <map>
#include <set>
#include <list>
#include <cmath>
#include <ctime>
#include <deque>
#include <queue>
#include <stack>
#include <bitset>
#include <cstdio>
#include <limits>
#include <vector>
#include <cstdlib>
#include <numeric>
#include <sstream>
#include <iostream>
#include <algorithm>
#include <functional>
#include <iomanip>
#include <unordered_map>
#include <memory.h>
#include <unordered_set>
#include <fstream>
#include <random>
using namespace std;
int h[301];
int dp[305][205][205];
int main(void)
{
cin.tie(0);
ios::sync_with_stdio(false);
int n;
cin >> n;
for (int i = 0; i < n; i++)
{
cin >> h[i];
}
for(int i=0;i<=300;i++)
{
for (int j = 0; j <= 200; j++)
{
for (int k = 0; k <= 200; k++)
{
dp[i][j][k] = 1e9;
}
}
}
dp[0][0][0] = 0;
for (int i = 0; i < n; i++)
{
for (int j = 0; j <= 200; j++)
{
for (int k = 0; k <= 200; k++)
{
if (dp[i][j][k] >= 1e9)
{
continue;
}
int a = j;
int b = k;
int c = h[i];
int m = min(a, min(b, c));
int cost = 7 * m + (a - m) * 3;
dp[i + 1][b - m][c - m] = min(dp[i + 1][b - m][c - m], dp[i][a][b] + cost);
m = min(a, b);
cost = 5 * m + (a - m) * 3;
dp[i + 1][b - m][c] = min(dp[i + 1][b - m][c], dp[i][a][b] + cost);
cost = 3 * a;
dp[i + 1][b][c] = min(dp[i + 1][b][c], dp[i][a][b] + cost);
}
}
}
int res = 1e9;
for (int i = 0; i <= 200; i++)
{
for (int j = 0; j <= 200; j++)
{
if (dp[n][i][j] >= 1e9)
{
continue;
}
int m = min(i, j);
int cost = dp[n][i][j] + 5 * m + (i - m) * 3 + (j - m) * 3;
res = min(res, cost);
}
}
cout << res << '\n';
return 0;
}
