#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include <debug.h>
#else
#define debug(...)
#endif
#define ft front
#define bk back
#define st first
#define nd second
#define ins insert
#define ers erase
#define pb push_back
#define pf push_front
#define _pb pop_back
#define _pf pop_front
#define lb lower_bound
#define ub upper_bound
#define mtp make_tuple
#define bg begin
#define ed end
#define all(x) (x).bg(), (x).ed()
#define sz(x) (int)(x).size()
typedef long long ll; typedef unsigned long long ull;
typedef double db; typedef long double ldb;
typedef pair<int, int> pi; typedef pair<ll, ll> pll;
typedef vector<int> vi; typedef vector<ll> vll; typedef vector<pi> vpi; typedef vector<pll> vpll;
typedef string str;
template<typename T> T gcd(T a, T b) { return (b == 0? a : gcd(b, a % b)); }
template<typename T> T lcm(T a, T b) { return a / gcd(a, b) * b; }
#define FOR(i, l, r) for (int (i) = (l); (i) <= (r); ++(i))
#define FOS(i, r, l) for (int (i) = (r); (i) >= (l); --(i))
#define FRN(i, n) for (int (i) = 0; (i) < (n); ++(i))
#define FSN(i, n) for (int (i) = (n) - 1; (i) >= 0; --(i))
#define EACH(i, x) for (auto &(i) : (x))
#define WHILE while
#define file "TEST"
mt19937 rd(chrono::steady_clock::now().time_since_epoch().count());
ll rand(ll l, ll r) { return uniform_int_distribution<ll>(l, r)(rd); }
/*
----------------------------------------------------------------
END OF TEMPLATE
----------------------------------------------------------------
Tran The Bao - ghostwriter
Training for VOI23 gold medal
----------------------------------------------------------------
DIT ME CHUYEN BAO LOC
----------------------------------------------------------------
*/
#define int long long
const int oo = 1e9 + 5;
const int N = 5e5 + 5;
int n, a[N], d[N];
ll d1[N], f[N], f1[N];
void upd(int ps, ll v) { for (int i = ps; i >= 1; i -= (i & -i)) f1[i] = min(f1[i], v); }
ll get(int ps) { ll rs = oo; for (int i = ps; i <= n; i += (i & -i)) rs = min(rs, f1[i]); return rs; }
signed main() {
ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
// freopen(file".inp", "r", stdin);
// freopen(file".out", "w", stdout);
cin >> n;
FOR(i, 1, n) {
cin >> a[i];
f[i] = f[i - 1] + a[i];
}
d[1] = 1;
d1[1] = a[1];
FOR(i, 1, n) f1[i] = oo;
upd(1, f[1] + d1[1]);
FOR(i, 2, n) {
int l = 1, r = i - 1, ans = -1;
WHILE(l <= r) {
int mid = l + (r - l) / 2;
if (f[i] >= get(mid)) {
ans = mid;
l = mid + 1;
}
else r = mid - 1;
}
if (ans != -1) {
d[i] = d[ans] + 1;
d1[i] = f[i] - f[ans];
}
else {
d[i] = d[i - 1];
d1[i] = f[i];
}
upd(i, f[i] + d1[i]);
}
cout << d[n];
return 0;
}
/*
14
6 4 4 6 9 1 10 9 1 2 5 10 10 10
6 4|4 6|9 1|10|9 1 2|5 10|10 10
0 0 1 0 1 0 1 1 0 0 1 0 1
----------------------------------------------------------------
From Benq:
stuff you should look for
* int overflow, array bounds
* special cases (n=1?)
* do smth instead of nothing and stay organized
* WRITE STUFF DOWN
* DON'T GET STUCK ON ONE APPROACH
----------------------------------------------------------------
*/
