#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using ll = long long;
#define rep(i,n) for(int i=0;i<(int)(n);i++)

int main(){
	int n;
	cin>>n;
	vector<int> d(n+1,0);
	int nw=0;
	int m;
	cin>>m;
	rep(i,m){
		int a;
		cin>>a;
		nw+=a;
		d.at(nw)=1;
	}
	cin>>m;
	rep(i,m){
		int b;
		cin>>b;
		nw-=b;
		d.at(nw)=1;
	}
	int ans=0;
	rep(i,n+1) if(!d.at(i)) ans++;
	cout<<ans<<endl;
}