#include <bits/stdc++.h>
#define ll long long
#define fi first
#define se second
#define sz(x) (int)x.size()
#define ALL(v) v.begin(),v.end()
#define MASK(k) (1LL << (k))
#define BIT(x, i) (((x) >> (i)) & 1)
#define oo (ll)1e18
#define INF (ll)1e9
#define MOD (ll)(1e9 + 19972207)
using namespace std;
template<class T1, class T2>
bool maximize(T1 &a, T2 b){if(a < b){a = b; return true;} return false;}
template<class T1, class T2>
bool minimize(T1 &a, T2 b){if(a > b){a = b; return true;} return false;}
template<class T1, class T2>
void add(T1 &a, T2 b){a += b; if(a >= MOD) a -= MOD;}
template<class T1, class T2>
void sub(T1 &a, T2 b){a -= b; if(a < 0) a += MOD;}
template<class T>
void cps(T &v){sort(ALL(v)); v.resize(unique(ALL(v)) - v.begin());}
const int MAX = 303;
int N;
int a[MAX];
ll f[MAX][202][202];
void solve(){
cin >> N;
for(int i=1; i<=N; i++){
cin >> a[i];
}
memset(f, 0x3f, sizeof f);
for(int i=0; i<=a[1]; i++){
f[1][0][a[1] - i] = f[2][a[1] - i][a[2]] = 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--){
minimize(f[i][j][k - 1], f[i][j][k] + 3);
}
}
for(int j=a[i - 1]; j>0; j--){
for(int k=a[i]; k>0; k--){
minimize(f[i][j - 1][k - 1], f[i][j][k] + 5);
}
}
if(i == N) break;
for(int j=min(a[i - 1], min(a[i], a[i + 1])); j>=0; j--){
for(int k=a[i]; k>=j; k--){
minimize(f[i + 1][k - j][a[i + 1] - j], f[i][j][k] + 7LL * j);
}
}
}
cout << f[N][0][0] << '\n';
}
int main(){
ios_base::sync_with_stdio(0); cin.tie(0);
// freopen("mmgraph.inp", "r", stdin);
// freopen("mmgraph.out", "w", stdout);
int t = 1;
// cin >> t;
while(t--){
solve();
}
return 0;
}
