#include<bits/stdc++.h>
using namespace std;
int a[1005];
bool is[1005];
int main()
{
    int n,m,ans = 0;
    cin >> n >> m;
    queue<int> q;
    for (int i = 1;i <= m;i++){
    	cin >> a[i];
    	is[a[i]] = false;
	}
	for (int i = 1;i <= m;i++){
		if (is[a[i]]){
			continue;
		}
		else{
			ans++;
			if (q.empty() == n){
				is[q.front()] = false;
				q.pop();
				q.push(a[i]);
				is[a[i]] = true;
			}
			else{
				q.push(a[i]);
				is[a[i]] = true;
			}
		}
	}
	cout << ans;
    return 0;
}