#include <bits/stdc++.h>
#define rep(i, a, n) for(int i = a; i < (n); i++)
using namespace std;
using ll = long long;
using P = pair<ll, ll>;
const int INF = 1001001001;
const ll LINF = 1001002003004005006ll;
//const int mod = 1000000007;
//const int mod = 998244353;

int main()
{
  int n;
  cin >> n;
  int m1;
  cin >> m1;
  vector<int> a(m1);
  rep(i, 0, m1) cin >> a[i];
  int m2;
  cin >> m2;
  vector<int> b(m2);
  rep(i, 0, m2) cin >> b[i];
  set<int> st;
  int now = 0;
  rep(i, 0, m1) {
    now += a[i];
    st.insert(now);
  }
  rep(i, 0, m2) {
    now -= b[i];
    st.insert(now);
  }
  cout << n - st.size() + 1 << endl;
  return 0;
}