#include <iostream>
#include <cassert>
#include <algorithm>
#include <vector>
#include <unordered_map>
#include "optimization.h"
#include <map>

#define all(a) a.begin, a.end()
using namespace std;

int main() {
    int n = readInt();

    map<int, bool> used;
    for (int i = 0; i < n; i++){
        int temp = readInt();
        used[temp] = true;
    }
    int m = readInt();
    int count = 0;
    for (int i = 0; i < m; i++){
        int temp = readInt();
        if (used[temp]){
            count++;
        }
    }
//    cout << count;
    writeInt(count);
}