#include <iostream>
#include <algorithm>
#include <vector>
#include <string>
#include <set>

using namespace std;

vector<int> a, b;
int n, m, alla[200001], allb[200001], col0[200001], col1[200001];

int main() {
    cin >> n;
    a.resize(n);
    for (int i = 0; i <= 2e5; i++) {
        alla[i] = -1;
        allb[i] = -1;
    }
    int cnt = 0;
    for (int i = 0; i < n; i++) {
        cin >> a[i];
        if (a[i] == 0) {
            cnt++;
            alla[cnt] = 0;
        }
        col0[i] = cnt;
    }
    cnt = 0;
    cin >> m;
    b.resize(m);
    for (int i = 0; i < m; i++) {
        cin >> b[i];
        if (b[i] == 0) {
            cnt++;
            allb[cnt] = 0;
        }
        col1[i] = cnt;
    }
    cnt = 0;
    for (int i = n - 1; i >= 0; i--) {
        if (a[i] == 1)
            cnt++;
        if (a[i] == 0) {
            alla[col0[i]] = cnt;
        }
    }
    alla[0] = cnt;
    cnt = 0;
    for (int i = m - 1; i >= 0; i--) {
        if (b[i] == 1)
            cnt++;
        if (b[i] == 0) {
            allb[col1[i]] = cnt;
        }
    }
    allb[0] = cnt;
    int q = -1;
    for (int i = 0; i <= 2e5; i++) {
        if (allb[i] != -1 && alla[i] != -1) {
            if (min(alla[i] + i, allb[i] + i) > q)
                q = min(alla[i] + i, allb[i] + i);
        }
    }
    cout << q;
    return 0;
}