#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
#define rep(i, n) for(int i=0;i<(n);++i)
#define rep1(i, n) for(int i=1;i<=(n);i++)
#define ll long long
using mint = modint998244353;
using P = pair<ll,ll>;
using lb = long double;
using T = tuple<ll, ll, ll>;
#ifdef LOCAL
#  include <debug_print.hpp>
#  define dbg(...) debug_print::multi_print(#__VA_ARGS__, __VA_ARGS__)
#else
#  define dbg(...) (static_cast<void>(0))
#endif

int main()
{
	int n, m1;
	cin >> n >> m1;
	vector<int> a(m1);
	rep(i,m1) cin >> a[i];
	vector<bool> vis(n+1);
	vis[0] = true;
	int now = 0;
	rep(i,m1){
		now += a[i];
		vis[now] = true;
	}
	int m2;
	cin >> m2;
	vector<int> b(m2);
	rep(i,m2) cin >> b[i];
	rep(i,m2){
		now -= b[i];
		vis[now] = true;
	}
	int ans = 0;
	rep(i,n+1){
		if(!vis[i])ans++;
	}
	cout << ans << endl;
	return 0;
}