#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define pb push_back
#define mp make_pair
#define ff first
#define ss second
const int N = 5*1e5+11;
int n, off = 1;
ll a[N], b[N], z[N], ak[N];
ll t[4*N], lazy[4*N];
void clear (int x) {
t[x] += lazy[x];
if (x < off) {
lazy[x*2] += lazy[x];
lazy[x*2+1] += lazy[x];
}
lazy[x] = 0;
}
ll update(int cf, int ct, int lf, int lt, ll c, int node) {
clear(node);
if (cf > lt || ct < lf) return t[node];
if (cf >= lf && ct <= lt) {
lazy[node] += c;
clear(node);
return t[node];
}
int mid = (cf+ct)/2;
update(cf, mid, lf, lt, c, node*2);
update(mid+1, ct, lf, lt, c, node*2+1);
return t[node] = max(t[node*2], t[node*2+1]);
}
int upit(int cf, int ct, int node) {
clear(node);
if (cf != ct) {
clear(node*2);
clear(node*2+1);
}
int mid = (cf+ct)/2;
if (cf == ct) return cf;
if (t[node*2+1] >= 0) return upit(mid+1, ct, node*2+1);
return upit(cf, mid, node*2);
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin >> n;
while (off < n+1) off *= 2;
for (int i=0;i<n;i++) {
cin >> a[i];
ak[i] = a[i];
if (i > 0) ak[i] += ak[i-1];
}
memset(t, -1, sizeof t);
b[0] = a[0]; z[0] = -1;
update(0, off-1, 0, 0, a[0]+1, 1);
for (int i=1;i<n;i++) {
update(0, off-1, i, i, -b[i-1]+1, 1);
update(0, off-1, 0, i, a[i], 1);
int pos = upit(0, off-1, 1);
z[i] = pos-1;
b[i] = ak[i];
if (pos > 0) b[i] -= ak[pos-1];
}
int br = 0;
int x = n-1;
while (x >= 0) {
br++;
x = z[x];
}
cout << br;
return 0;
}
