#include<iostream>
#include<vector>

using namespace std;

int main(){
	int N,M;
	cin >> N >> M;
	vector<int> count(M+1,0);
	int ans=0;
	for(int i=0;i<N;i++){
		int A;
		cin >> A;
		count[A]++;
	}
	
	for(int i=1;i<=M;i++){
		int B;
		cin >> B;
		if(B<count[i]){
			ans+=count[i]-B;
		}
	}
	cout << ans << "\n";
}