#include<bits/stdc++.h>
using namespace std;
int main()
{
    int n;
    cin >> n;
    
    vector<int> arr(n);
    
    for(int i=0;i<n;i++)
    cin >> arr[i];
    
    int val;
    cin >> val;
    
    map<int,int> hmap;
    
    int presum=0;
    int maxlen=0;
    for(int i=0;i<n;i++)
    {
        presum+=arr[i];
        if(sum==val)
        maxlen=max(maxlen,i+1);
        int rem=sum-val;
        if(hmap.find(rem)!=hmap.end())
        {
            int len=i-hmap[rem];
            maxlen=max(maxlen,len);
        }hmap[presum]=i;
    }cout<<maxlen;
}