#include <bits/stdc++.h>
using namespace std;
int main()
{
	int m,n,a[1005],b[1005],flag,cnt=0;
	cin>>m>>n;
	for(int i=1;i<=n;i++)cin>>a[i];
	int L=0,R=1;
	memset(b,-1,sizeof(b));
	for(int i=1;i<=n;i++)
	{
		flag=1;
		for(int j=L;j<=R;j++)
		{
			if(b[j]==a[i])
			{
				flag=0;
				break;	
			}
		}
		if(flag)
		{
			cnt++;
			if(R-L>=m)L++;
			b[R++]=a[i];
		}
	}
cout<<cnt<<endl;
return 0;
}

/**************************************************************
	Problem: 2104
	User: admin
	Language: C++
	Result: Accepted
	Time:48 ms
	Memory:2072 kb
****************************************************************/