#include <bits/stdc++.h>
using namespace std;
using ll = long long;

template<class T> istream& operator >> (istream& is, vector<T>& vec) {
    for(T& x : vec) is >> x;
    return is;
}

template<class T> ostream& operator << (ostream& os, const vector<T>& vec) {
    if(vec.empty()) return os;
    os << vec[0];
    for(auto it = vec.begin(); ++it != vec.end(); ) os << ' ' << *it;
    return os;
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n, m1, m2;
    cin >> n >> m1;
    vector<int> a(m1);
    cin >> a >> m2;
    vector<int> b(m2);
    cin >> b;
    vector<bool> used(n + 1);
    used[0] = true;
    int s = 0;
    for(int i = 0; i < m1; i++){
        s += a[i];
        used[s] = true;
    }
    s = n;
    for(int i = 0; i < m2; i++){
        s -= b[i];
        used[s] = true;
    }
    cout << n + 1 - count(used.begin(), used.end(), true) << '\n';
}