#include <bits/stdc++.h>
using namespace std;

int main() {
	int a[150], a1[1500];  
	int n, m;
	cin >> n >> m;
	memset(a, 0, sizeof(a));
	memset(a1, 0, sizeof(a1));
	int tt = 1;  
	int num = 0;  
	for (int i = 1; i <= m; i++) {
		int x;
		cin >> x;
		if (a1[x] == 0) {
			num++;  
			if (tt > n) {  
				int old = a[1];  
				a1[old] = 0;  
				for (int j = 1; j < n; j++) {
					a[j] = a[j + 1];
				}
				tt = n;  
			}
			a[tt] = x;  
			a1[x] = 1; 
			tt++;  
		}
		
	}
	cout << num;
	return 0;
}