#include <bits/stdc++.h>
using namespace std;
#define int long long
#define rep(x, a, b) for(auto x=a;(a<b?x<b:x>b);(a<b?x++:x--))
#define all(a) a.begin(), a.end()
#define srtvc(a) sort(all(a))
#define bcsrtvc(a) sort(all(a), greater<__typeof__(a[0])>())
#define ppf pop_front
#define ppb pop_back
#define pf push_front
#define pb push_back
#define ef emplace_front
#define eb emplace_back
#define fr first
#define sc second
#define pq priority_queue
#define pii pair<int, int>
#define vc vector
#define dq deque
#define sz(a) a.size()
#define mnto(x,y) x = min(x, (__typeof__(x))y)
#define mxto(x,y) x = max(x, (__typeof__(x))y)
#define setval(arr, x) memset(arr, x, sizeof(arr))
template<typename T>
using vv = vc<vc<T>>;
struct Line {
__int128 m, c;
Line(__int128 _m, __int128 _c) : m(_m), c(_c) {}
__int128 eval(__int128 x) const { return m * x + c; }
};
struct CHT {
vc<Line> hull;
bool bad(const Line &L1, const Line &L2, const Line &L3) {
__int128 left = (L2.c - L1.c) * (L1.m - L3.m);
__int128 right = (L3.c - L1.c) * (L1.m - L2.m);
return left <= right;
}
void add(__int128 m, __int128 c) {
Line L(m, c);
while (sz(hull) >= 2 && bad(hull[sz(hull)-2], hull.back(), L)) hull.ppb();
hull.pb(L);
}
__int128 query(__int128 x) {
int l = 0, r = sz(hull) - 1;
while (l < r) {
int mid = (l + r) >> 1;
if (hull[mid].eval(x) <= hull[mid+1].eval(x)) r = mid;
else l = mid+1;
}
return hull[l].eval(x);
}
};
int32_t main() {
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
int n;
cin >> n;
vc<int> t(n);
rep(i, 0, n) cin >> t[i];
rep(i, 1, n) mxto(t[i], t[i-1]);
__int128 ans = 0;
CHT cht;
rep(i, n-1, -1) {
cht.add(-(__int128)t[i], (__int128)t[i]*n+ans);
ans = cht.query(i);
}
cout << (int)ans;
}
