#include <bits/stdc++.h>
using namespace std;
#define int long long
const int INF = 1e18;
const int N = 2e5 + 5;
int a[N], pr[N], cur[N], dp[N][2], n, best = 0;
array < int , 2 > st[N * 4];
array < int , 2 > merge(array < int , 2 > l, array < int , 2 > r){
if(l[0] < r[0])return l;
if(l[0] > r[0])return r;
array < int , 2 > rs = l;
if(l[1] < r[1])rs[1] = r[1];
return rs;
}
void upd(int v, int l, int r, int pos, int val){
if(l == r){
st[v] = {val, l};
return;
}
int mid = (l + r) >> 1;
if(mid >= pos)upd(v * 2, l, mid, pos, val);
else upd(v * 2 + 1, mid + 1, r, pos, val);
st[v] = merge(st[v * 2], st[v * 2 + 1]);
}
void ask(int v, int l, int r, int cur){
if(st[v][0] <= cur)
best = max(best, st[v][1]);
if(l == r)return;
int mid = (l + r) >> 1;
if(st[v * 2][0] <= cur)ask(v * 2, l, mid, cur);
if(st[v * 2 + 1][0] <= cur)ask(v * 2 + 1, mid + 1, r, cur);
}
signed main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
cin >> n;
for(int i = 1; i <= n; i++){
cin >> a[i];
pr[i] = pr[i - 1] + a[i];
dp[i][0] = -1;
dp[i][1] = INF;
upd(1, 1, n, i, INF);
}
dp[1][0] = 1;
dp[1][1] = a[1];
upd(1, 1, n, 1, a[1] + pr[1]);
for(int i = 2; i <= n; i++){
best = 0;
ask(1, 0, n, pr[i]);
dp[i][1] = min(dp[i][1], pr[i] - pr[best]);
upd(1, 1, n, i, dp[i][1] + pr[i]);
dp[i][0] = dp[best][0] + 1;
}
cout << dp[n][0] << endl;
}
