#include <iostream>
#include <fstream>
#include <unordered_map>
#include <numeric>

using namespace std;

const int MAX_N = 100000 + 1;

long long A[MAX_N];
long long B[MAX_N];

int main()
{
   /// ifstream cin("data.in");

    int N;
    cin >> N;

    for (int i = 1; i <= N; ++i)
        cin >> A[i];

    for (int j = 1; j <= N; ++j)
        cin >> B[j];

    partial_sum(A + 1, A + N + 1, A + 1);
    partial_sum(B + 1, B + N + 1, B + 1);

    unordered_map<long long, int> UMap;

    UMap.insert({0, 0});

    int best = 0;

    for (int i = 1; i <= N; ++i)
    {
        long long d = A[i] - B[i];

        auto it = UMap.find(d);

        if (it != UMap.end())
        {
            best = max(best, i - it->second);
        }
        else
            UMap.insert({d, i});
    }

    cout << best << endl;

    return 0;
}