#include<bits/stdc++.h>
using namespace std;
int m,n;
int s[1005],a[1005],t[105],f,ans;//t数组存内存内的译文
int main()
{	
	cin>>m>>n;
	for(int i = 1;i<=n;i++){
		cin>>s[i];
	}
	int head = 1,tail = 1;
	for(int i = 1;i<=n;i++){
		f = 0;
		for(int j = head;j<=tail;j++){
			if(s[i] == t[j]){//内存中有没有
				f = 1;
				break;
			}
		}
		if(f==0){
			ans++;
			if(tail-head == m){
				head++;
				}
			t[tail++] = s[i];
		}
		
	} 
	cout<<ans;
	return 0;
}