#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef long double ld;
typedef pair<ll, ll> pl;
typedef vector<ll> vl;
typedef vector<pl> vp;
#define nl "\n"
#define fr first
#define sc second
#define pb push_back
#define all(x) x.begin(), x.end()
#define fur(i, a, b) for(ll i = a; i <= b; ++i)
#define ruf(i, a, b) for(ll i = a; i >= b; --i)
#define pv(x) for(auto k : x){cout << k << " ";} cout << nl
const ll inf = 1e17;
struct dt{
ll cost, li, wt;
dt(){
cost = li = wt = inf;
}
void print(){
cout << cost << ' ' << li << ' ' << wt << nl;
}
};
ll n, sz;
vl t, st;
ll maxr(ll l, ll r, ll k, ll kl, ll kr){
if (kl > r || kr < l)
return 0;
if (kl >= l && kr <= r)
return st[k];
ll m = (kl + kr)/2;
return max(maxr(l, r, 2 * k, kl, m), maxr(l, r, 2 *k + 1, m + 1, kr));
}
void solve(){
vector<pl> dp;
dp.resize(n + 1, {inf, inf});
//dp[0] = {0, 0, 0};
dp[0] = {0, 0};
//dp[1] = {t[1], t[1]};
fur(i, 1, n){
fur(j, 0, i - 1){ // i -> i - 1
ll mx = maxr(j + 1, i, 1, 1, sz);
// fur(p, j + 1, i)
// mx = max(mx, t[p]);
ll cost = (mx + dp[j].sc) * (i - j);
if (dp[j].fr + cost < dp[i].fr){
dp[i].fr = dp[j].fr + cost;
dp[i].sc = dp[j].sc + mx;
}
}
}
cout << dp[n].fr << nl;
}
int main(){
ios::sync_with_stdio(0);
cin.tie(0);
cin >> n;
t.resize(n + 1);
t[0] = 0;
fur(i, 1, n)
cin >> t[i];
sz = n;
while(__builtin_popcountll(sz) != 1)
sz++;
st.resize(2*sz, 0);
fur(i, 0, n - 1)
st[i + sz] = t[i + 1];
ruf(i, sz - 1, 1)
st[i] = max(st[2 * i], st[2*i + 1]);
solve();
return 0;
}
