//496
#include <bits/stdc++.h>
using namespace std;
const int N = 1010;
int a[N], b[N], t=-1,head,cnt=0, r, n, m;
int main(){
cin >> n >> m;
for (int i = 0; i < m; i++) cin >> a[i];
for (int i = 0; i < m; i++){
for (int j = head; j <= t; j++){
if (a[i] == b[j]){
r = 1;
break;
}
}
if (r!=1) b[++t] = a[i],cnt++;
if (t - head > n - 1) head++;
r = 0;
}
cout<< cnt;
return 0;
}