#include <bits/stdc++.h>

using namespace std;

#define ll long long
#define ld long double
#define pb push_back
#define mp make_pair
#define pii pair<int, int>
#define pll pair<ll, ll>
#define pdd pair<ld, ld>
#define all(x) (x).begin(), (x).end()
#define fi first
#define se second

const int NMAX = 100005;

int a[NMAX], b[NMAX];
unordered_map<ll, int> m;

int main() {
    cin.sync_with_stdio(false);

    int n;
    cin >> n;

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

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

    ll s1 = 0, s2 = 0;
    m[0] = 0;
    int sol = 0;
    for (int i = 1; i <= n; i++) {
        s1 += a[i];
        s2 += b[i];

        if (m.count(s1 - s2)) {
            int mlc = m[s1 - s2];
            sol = max(sol, i - mlc);
        }

        if (!m.count(s1 - s2)) {
            m[s1 - s2] = i;
        }
    }

    cout << sol;

    return 0;
}