#include <bits/stdc++.h>
using namespace std;
const int MAXN = 505;
int dp[MAXN][MAXN], dp1[MAXN], d[MAXN], sp[MAXN];
int sum(int i, int j){
return sp[j] - sp[i-1];
}
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
int n; cin>>n;
for(int i = 1; i <= n; i++){
cin>>d[i];
sp[i] = sp[i-1]+d[i];
}
int ans = 0;
for(int l = n-1; l >= 1; l--)
for(int r = l; r < n; r++){
set<int> st;
for(int i = l; i < r; i++)st.insert(sum(i+1,r));
//cout<<l<<" "<<r<<": ";
//for(int x : st)cout<<x<<" "; cout<<" | ";
int qtd = 0;
for(int j = r+1; j < n; j++)
if(st.find(sum(r+1,j)) != st.end()){
qtd++;
dp[l][r] = max(dp[l][r], dp1[r+1]+qtd);
}
//cout<<dp[l][r]<<" ";
//cout<<qtd<<"\n";
ans = max(ans,dp[l][r]);
dp1[l] = max(dp1[l],dp[l][r]);
}
cout<<ans<<"\n";
}
