#include <iostream>
#include <vector>
using namespace std;
int main(void){
    int n, m1, m2;
    cin >> n;
    vector<bool> ds(n+1);
    ds[0] = true;
    ds[n] = true;
    int dsc = 2;
    cin >> m1;
    int a, ups = 0;
    for (int i = 0; i < m1; i++) {
        cin >> a;
        ups += a;
        if (!ds[ups]) {
            ds[ups] = true;
            dsc++;
        }
    }
    cin >> m2;
    int b, dws = n;
    for (int i = 0; i < m2; i++) {
        cin >> b;
        dws -= b;
        if (!ds[dws]) {
            ds[dws] = true;
            dsc++;
        }
    }
    cout << n+1 - dsc << endl;
}