#include <iostream>
#include <algorithm>
#include <functional>
#include <atcoder/maxflow>
#define rep(i, n) for(i = 0; i < n; i++)
#define int long long
using namespace std;
using namespace atcoder;

const int INF = 1e+9;
int n, a;
int b[50];
int c;
int d[50];

signed main() {
    int i, j;

    cin >> n >> a;
    rep(i, a) cin >> b[i];
    cin >> c;
    rep(i, c) cin >> d[i];
    sort(b, b + a, greater<int>());
    sort(d, d + c);

    mf_graph<int> g(a + c + 2);
    int s = a + c, t = s + 1;

    rep(i, a) {
        int x = n / a;
        if (i < n % a) x++;
        g.add_edge(s, i, x);
    }

    rep(i, c) {
        int x = n / c;
        if (i < n % c) x++;
        g.add_edge(a + i, t, x);
    }

    rep(i, a) {
        rep(j, c) {
            if (b[i] > d[j]) {
                g.add_edge(i, a + j, INF);
            }
        }
    }

    cout << g.flow(s, t) << endl;
    return 0;
}