#include <iostream>
#include <map>
using namespace std;

const int MAX_N = 100100;

map<long long, int> M;

int a[MAX_N];
int b[MAX_N];

int main() {
    int n;
    cin >> n;
    for(int i = 1; i <= n; i++) {
        cin >> a[i];
    }
    for(int i = 1; i <= n; i++) {
        cin >> b[i];
    }

    long long sum = 0;
    M[0] = 0;
    int ans = 0;
    for(int i = 1; i <= n; i++) {
        sum += a[i] - b[i];
        if(M.find(sum) != M.end()) {
            ans = max(ans, i - M[sum]);
        }
        else {
            M[sum] = i;
        }
    }

    cout << ans;

    return 0;
}