#include <iostream>
#include <map>
#include <vector>
#include <algorithm>
using namespace std;
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
int a, b, sum = 0;
cin >> a >> b;
map<int, bool> m;
for (int i = 0; i < a + b; i++) {
int tmp;
cin >> tmp;
if (m[tmp] == true)
m.erase(tmp);
else
m[tmp] = true;
}
cout << m.size();
}