#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define fi first
#define sc second
#define pll pair<ll,ll>
#define pii pair<int,int>
#define all(x) (x).begin(),(x).end()
const ll nmax = 5e5+6;
const ll inf = 1e18;
ll a[nmax];
ll pref[nmax];
ll n;
struct segtre{
ll st[nmax * 4];
void init(int n){
for(int i = 1;i<=4*n;i++) st[i] = inf;
}
void update(int id,int l,int r,int i,ll x){
if(i>r ||i <l) return;
if(l==r) {
st[id] = x;
return;
}
int mid = (l+r)/2;
update(id*2,l,mid,i,x);
update(id*2+1,mid+1,r,i,x);
st[id] = min(st[id*2],st[id*2+1]);
}
ll walk(int id,int l,int r,ll x){
if (l==r) return l ;
int mid = (l+r)/2;
if(st[id*2] <= x) return walk(id*2,l,mid,x);
return walk(id*2+1,mid+1,r,x);
}
} tree;
ll dp[nmax];
ll f[nmax];
void solve(){
cin >> n;
for(int i = 1;i<=n;i++){
cin >> a[i];
// pref[i] = pref[i-1] + a[i];
}
reverse(a + 1, a + n + 1);
tree.init(n+1);
tree.update(1,1,n+1,n+1,0);
for(int i = n;i>=1;i--){
pref[i] = pref[i+1] + a[i];
int get = tree.walk(1,1,n+1,pref[i]);
// cout << get << '\n';
f[i] = pref[i] - pref[get];
dp[i] = dp[get] + 1;
tree.update(1,1,n+1,i,f[i] + pref[i]);
}
// cout << f[2];
cout << dp[1];
}
int main(){
ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
solve();
}
