#include <bits/stdc++.h>
using namespace std;
#define oo 1e15
#define fi first
#define se second
#define sp(iiii) setprecision(iiii)
#define IO ios_base::sync_with_stdio(false); cin.tie(0)
#define ms(aaaa,xxxx) memset(aaaa,xxxx,sizeof(aaaa))
#define cntbit(xxxx) __builtin_popcount(xxxx)
#define getbit(xxxx,aaaa) ((xxxx>>(aaaa-1))&1)
typedef long double ld;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef pair<pair<int,int>,int> piii;
typedef pair<long long,long long> pll;
typedef pair<pair<long long,long long>,long long> plll;
typedef pair<pair<long long,long long>,pair<long long,long long>> pllll;
typedef pair<pair<long long,long long>,bool> pllb;
const ll base=361;
const ll mod=998244353;
const ld eps=1e-5;
const ll maxn=1e9+9;
ll n,i,j,a[1000009],f[1000009],sizet;
struct segtree_ele{
pll line;
ll l,r;
} segtree[30000009];
ll getval(pll line,ll gt) {
return line.fi*gt+line.se;
}
ll getnode(ll &x) {
if (x!=0) {
return x;
}
sizet++;
x=sizet;
segtree[x].l=0;
segtree[x].r=0;
segtree[x].line={0,-oo};
return x;
}
void update(ll id,ll l,ll r,pll line) {
if (line.fi<segtree[id].line.fi) {
swap(segtree[id].line,line);
}
if (line.fi==segtree[id].line.fi) {
segtree[id].line.se=max(segtree[id].line.se,line.se);
return;
}
if (r-l==1) {
return;
}
ll mid=(r+l)/2;
if (getval(line,l)>getval(segtree[id].line,l)) {
swap(line,segtree[id].line);
update(getnode(segtree[id].l),l,mid,line);
}
else {
if (getval(line,mid)>getval(segtree[id].line,mid)) {
swap(segtree[id].line,line);
update(getnode(segtree[id].l),l,mid,line);
}
else {
update(getnode(segtree[id].r),mid,r,line);
}
}
}
ll get(ll id,ll l,ll r,ll gt) {
if (r-l==1) {
return getval(segtree[id].line,gt);
}
ll mid=(r+l)/2;
if (gt<mid) {
return max(getval(segtree[id].line,gt),get(getnode(segtree[id].l),l,mid,gt));
}
else {
return max(getval(segtree[id].line,gt),get(getnode(segtree[id].r),mid,r,gt));
}
}
int main(){
IO;
sizet=0;
getnode(n);
cin>>n;
for (i=1;i<=n;i++) {
cin>>a[i];
a[i]=max(a[i-1],a[i]);
}
update(1,1,maxn,{0,0});
for (i=1;i<=n;i++) {
f[i]=-get(1,1,maxn,a[i])+n*a[i];
update(1,1,maxn,{i,-f[i]});
}
cout<<f[n]<<'\n';
}
