#include <bits/stdc++.h>

using namespace std;
typedef long long ll;
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<ll> VL;
typedef vector<VL> VVL;
typedef pair<int, int> PII;

#define FOR(i, a, n) for (int i = (int)a; i < (int)n; ++i)
#define REP(i, n) FOR(i, 0, n)
#define ALL(x) x.begin(), x.end()
#define MOD 1000000007
#define INF 1000000000
#define PI 3.14159265359
#define EPS 1e-12

int main(void)
{
  int a, c, w[15], b[15], dp[2][25];
  cin >> a;
  REP(i, a) cin >> w[i];
  cin >> c;
  REP(i, c) cin >> b[i];
  sort(w, w+a); sort(b, b+c);
  /*REP(i, a) cout << w[i] << " "; cout << endl;
  REP(i, c) cout << b[i] << " "; cout << endl;*/
  REP(i, 25) dp[0][i] = dp[1][i] = INF;
  dp[0][0] = dp[1][0] = 0;
  /*REP(i, 10) cout << dp[0][i] << " "; cout << endl;
  REP(i, 10) cout << dp[1][i] << " "; cout << endl;*/
  for(int i=1; i<=20; ++i) {
    for(int j=0; j<a; ++j) {
      if(dp[1][i-1] < w[j]) {
        dp[0][i] = w[j];
        break;
      }
    }
    for(int j=0; j<c; ++j) {
      if(dp[0][i-1] < b[j]) {
        dp[1][i] = b[j];
        break;
      }
    }
    /*cout << i << ":" << endl;
    REP(i, 10) cout << dp[0][i] << " "; cout << endl;
    REP(i, 10) cout << dp[1][i] << " "; cout << endl;*/
  }


  int ans = 0;
  for(int i=1; i<=20; ++i) {
    if(dp[0][i] != INF) ans = i;
    if(dp[1][i] != INF) ans = i;
  }
  cout << ans << endl;

  return 0;
}