baekjoon14425.cpp

#include <iostream>
#include <unordered_map>
#include <string>

using namespace std;

int N, M, cnt;
string word;

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	cin >> N >> M;
	unordered_map<string, bool> m;
	for (int i = 0; i < N; i++) {
		cin >> word;
		m[word] = true;
	}
	for (int i = 0; i < M; i++) {
		cin >> word;
		if (m[word])
			cnt++;
	}
	cout << cnt;
}