#include<bits/stdc++.h>
#define ll long long
#define ull unsigned ll
#define epb emplace_back
#define pb push_back
#define ff first
#define ss second
#define pii pair<int,int>
#define pll pair<ll,ll>
#define inf 1e9+1
#define linf 1e18+1
using namespace std;
const int NMAX=2e7+1;
void solve(){
int n;cin>>n;
ll dp[n+1];
ll DP[n+1];
ll a[n+1];
for(int i=1;i<=n;i++)cin>>a[i];
ll pref[n+1];
pref[0]=0;
for(int i=1;i<=n;i++){
pref[i]=pref[i-1]+a[i];
dp[i]=1,DP[i]=pref[i];
}
dp[0]=0,DP[0]=0;
for(int i=0;i<=n;i++){
int l=i,r=n+1;
while(l+1<r){
int mid=(l+r)/2;
if(pref[mid]-pref[i]>=DP[i])r=mid;
else l=mid;
}
if(r==n+1){
if(i<n){
if(dp[i+1]>dp[i])continue;
if(dp[i+1]==dp[i]){
DP[i+1]=min(DP[i+1],DP[i]+a[i+1]);
continue;
}
dp[i+1]=dp[i];
DP[i+1]=DP[i]+a[i+1];
}
continue;
}
if(dp[r]>dp[i]+1)continue;
dp[r]=dp[i]+1;
DP[r]=pref[r]-pref[i];
if(i<n){
if(dp[i+1]>dp[i])continue;
if(dp[i+1]==dp[i]){
DP[i+1]=min(DP[i+1],DP[i]+a[i+1]);
continue;
}
dp[i+1]=dp[i];
DP[i+1]=DP[i]+a[i+1];
}
}
cout<<dp[n];
}
int main(){
ios_base::sync_with_stdio(false);cin.tie(0);
//sieve();
int test=1;//cin>>test;
while(test--)solve();
return 0;
}
