#include<cstdio>
#include<iostream>
#include<queue>
using namespace std;
bool check[1005];
int Main(){
	freopen("translate.in","r",stdin);
	freopen("translate.out","w",stdout);
	queue<short> q;
	short m,n;
	scanf("%d %d",&m,&n);
	short temp;
	int tot=0,size=0;
	for(int i = 1;i<=n;++i){
		scanf("%d",&temp);
		if(!check[temp]){
			tot++;
			if(size==m){
				check[q.front()]=false;
				q.pop();
			}
			else size++;
			check[temp]=true;
			q.push(temp);
		}
	}
	printf("%d",tot);
	return 0;
}
int work=Main();
int main(){;
}