#include<iostream>
#include<string>
#include<algorithm>
#include<cctype>
#include<set>
#include<bitset>
#include<math.h>
#include<map>
#include<queue>
#include<iomanip>
using namespace std;

int main(){
    int n, m1, m2, cnt = 0;
    cin >> n >> m1;
    vector<int> a(n+1);
    for (int i = 0; i < m1; i++){
        int temp;
        cin >> temp;
        cnt += temp;
        a[cnt]++;
    }
    cin >> m2;  
    for (int i = 0; i < m2; i++){
        int temp;
        cin >> temp;
        cnt -= temp;
        a[cnt]++;
    }
    for (int i = 0; i < n+1; i++){
        if (!(a[i])) cnt++;
    }
    cout << cnt << endl;
}