#include <bits/stdc++.h>

using namespace std;

ifstream fin("siruri4.in");
ofstream fout("siruri4.out");

int n, ab[100001], sp[100001], a, b;


int main(){
    fin >> n;
    for(int i = 1;i<=n;i++){
        fin >> a;
        ab[i] = a;
    }
    for(int i = 1;i<=n;i++){
        fin >> b;
        ab[i]-=b;
    }
    for(int i = 1;i<=n;i++){
        sp[i]=sp[i-1]+ab[i];
    }
    int max=0, nrmax;
    for(int i = 1;i<=n;i++){
        for(int j = 1;j<=n;j++){
            if(sp[i]==sp[j]){
                if((j-1)>max)
                    max=j-1,nrmax=sp[i];
            }
        }
    }
    fout << max-1;
}