#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef pair<int,int> P;
#define REP(i,n) for(int i=0;i<int(n);i++)

int s[200010];

int main(void){
	cin.tie(nullptr);  ios_base::sync_with_stdio(false);
	int i,j,k;

	int N,M1,M2;
	cin >> N >> M1;

	s[0]=1;
	int x=0;
	REP(i,M1){
		int a;
		cin >> a;
		x+=a;
		s[x]=1;
	}

	cin >> M2;
	x=N;
	REP(i,M2){
		int a;
		cin >> a;
		x-=a;
		s[x]=1;
	}

	int ans=0;
	REP(i,N+1) if(s[i]==0) ans++;

	cout << ans <<endl;


	return 0;
}