#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long double ld;
typedef pair <ll, ll> pl;
typedef pair <ld, ld> pd;

#define x first
#define y second
#define pb push_back

const ll INF = 2 * 1e9 + 100;
const ll M = 1e4 + 100;
const ll N = 1e6 + 100;

ll a[N], b[N], sl1[N], sl2[N], sr1[N], sr2[N];
vector <ll> n1, n2;

int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    ll n, m, ans = -INF;
    cin >> n;

    for (ll i = 0; i < n; i++)
        cin >> a[i];

    cin >> m;
    for (ll i = 0; i < m; i++)
        cin >> b[i];

    ll cnt1 = 0, cnt2 = 0;
    sl1[0] = a[0];

    for (ll i = 1; i < n; i++)
        sl1[i] = sl1[i - 1] + a[i];

    sr1[n - 1] = a[n - 1];
    for (ll i = n - 2; i >= 0; i--)
        sr1[i] = sr1[i + 1] + a[i];


    for (ll i = 0; i < n; i++)
    {
        if (!a[i])
            n1.pb(i);
        cnt1 += (a[i] == 0);
    }

    sl2[0] = b[0];
    for (ll i = 1; i < m; i++)
        sl2[i] = sl2[i - 1] + b[i];

    sr2[m - 1] = b[m - 1];
    for (ll i = m - 2; i >= 0; i--)
        sr2[i] = sr2[i + 1] + b[i];


    for (ll i = 0; i < m; i++)
    {
        if (!b[i])
            n2.pb(i);
        cnt2 += (b[i] == 0);
    }

    ans = max(ans, min(sl1[n - 1], sl2[m - 1]));
    ll cnt = min(cnt1, cnt2);

    for (ll i = 0; i < cnt; i++)
        ans = max(ans, i + min(sr1[n1[i]], sr2[n2[i]]) + 1);

    cout << ans << endl;
    return 0;
}