#include<iostream>
#include<cstdlib>
#include<cstdio>
#include<cstring> 
using namespace std;
char str[1005];
int N,M,f,flag,ans;
int head,tail;
int inl[1005];
/*int hashing()
{
    int ret=2;
    for (int i=0;i<=strlen(str)-1;i++)
    {
        ret+=(i+1)*int(str[i]);
        ret%=49999;
    }
    return ret;
}*/
int main()
{
    freopen("translate.in","r",stdin);
	freopen("translate.out","w",stdout); 
	cin>>M>>N;
    head=1;tail=0;ans=0;    //跪在这儿多少次。。
    for (int i=1;i<=N;i++)
    {
        cin>>f;
        flag=0;
        for (int j=head;j<=tail;j++)
        {
            if (f==inl[j]) {flag=1;break;} 
        }
        if (flag==0)
        {
            ans++;
            tail++;
            inl[tail]=f;
            while ((tail-head+1)>M) head++;
        }
    }
    cout<<ans<<endl;
    return 0;    
}