//雪花飄飄北風嘯嘯
//天地一片蒼茫
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/rope>
using namespace std;
using namespace __gnu_pbds;
using namespace __gnu_cxx;
#define ll long long
#define ii pair<ll,ll>
#define iii pair<ii,ll>
#define fi first
#define se second
#define endl '\n'
#define debug(x) cout << #x << " is " << x << endl
#define pub push_back
#define pob pop_back
#define puf push_front
#define pof pop_front
#define lb lower_bound
#define ub upper_bound
#define rep(x,start,end) for(auto x=(start)-((start)>(end));x!=(end)-((start)>(end));((start)<(end)?x++:x--))
#define all(x) (x).begin(),(x).end()
#define sz(x) (int)(x).size()
#define indexed_set tree<ll,null_type,less<ll>,rb_tree_tag,tree_order_statistics_node_update>
//change less to less_equal for non distinct pbds, but erase will bug
mt19937 rng(chrono::system_clock::now().time_since_epoch().count());
int n;
int arr[5005];
int memo[5005][5005];
int temp[5005];
int ptemp[5005];
int main(){
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
cin.exceptions(ios::badbit | ios::failbit);
cin>>n;
rep(x,1,n+1) cin>>arr[x];
temp[0]=ptemp[0]=-1e9;
rep(x,2,n){
rep(y,1,x) temp[y]=memo[y][x-1];
rep(y,1,x) ptemp[y]=max(ptemp[y-1],temp[y]);
int b=x-1;
int bs=0;
int fs=0;
int curr=0;
int add=0;
rep(y,x,n+1){
if (y!=x) fs+=arr[y-1];
while (bs<fs){
if (b){
curr=max(curr,temp[b]);
bs+=arr[b--];
}
else break;
}
//cout<<x<<" "<<y<<" "<<b<<" "<<bs<<" "<<fs<<endl;
if (y!=x && bs==fs){
curr--;
add++;
}
memo[x][y]=ptemp[b]+add;
memo[x][y]=max(memo[x][y],curr+add);
//cout<<x<<" "<<y<<" "<<memo[x][y]<<endl;
}
}
int ans=0;
rep(x,1,n+1) ans=max(ans,memo[x][n]);
cout<<ans<<endl;
}
