// Ivan Carvalho

// Solution to https://www.beecrowd.com.br/judge/problems/view/1104

#include <algorithm>

#include <cstdio>

#include <set>

using namespace std;

int main() {

int a, b;

while (scanf("%d %d", &a, &b) && (a || b)) {

int c = 0, d = 0;

set<int> A, B;

for (int i = 0; i < a; i++) {

int davez;

scanf("%d", &davez);

A.insert(davez);

}

for (int i = 0; i < b; i++) {

int davez;

scanf("%d", &davez);

B.insert(davez);

}

set<int>::iterator it;

for (it = A.begin(); it != A.end(); it++)

if (!B.count(*it)) c++;

for (it = B.begin(); it != B.end(); it++)

if (!A.count(*it)) d++;

printf("%d\n", min(c, d));

}

return 0;

}