#include<iostream>
#include<algorithm>
#include<vector>
#include<fstream>
using namespace std;
typedef long long ll;
typedef pair<ll,ll> P;
#define rep(i,n) for(int i=0;i<n;i++)
#define all(x) x.begin(),x.end()
#define chmin(a,b) a=min(a,b)
#define chmax(a,b) a=max(a,b)
#define N 500010
ll n,a[N],s[N];
ll dp[N],dq[N];
int main(){
cin.tie(0);
ios::sync_with_stdio(0);
cin>>n;
rep(i,n)cin>>a[i];
s[0]=0;
rep(i,n)s[i+1]=s[i]+a[i];
rep(i,n+1)dp[i]=1e18;
dp[0]=0;
dq[0]=0;
//for(int k=1;k<=n;k++){
vector<ll> score,place;
//scoreは単調増加
for(int i=0;i<=n;i++){
ll l=-1,r=score.size(),mid;
while(l<r-1){
mid=(l+r)>>1;
if(s[i]>=score[mid])l=mid;
else r=mid;
}
if(l>=0){
dp[i]=s[i]-s[place[l]];
dq[i]=dq[place[l]]+1;
}
ll sc=dp[i]+s[i];
while(score.size()>0){
if(score.back()>=sc){
score.pop_back();
place.pop_back();
}
else break;
}
score.push_back(sc);
place.push_back(i);
}
//}
cout<<dq[n]<<endl;
}
