//496
#include <bits/stdc++.h>
using namespace std;
int main(){
int n, m, a[1005], x, h = 0, ans = 0;
memset(a, -1, sizeof(a));
cin >> m >> n;
for(int i = 1;i <= n;i++){
cin >> x;
int b = 1;
for(int j = 0;j < m;j++){
if(x == a[j]){
b = 0;
break;
}
}
if(b == 1){
a[++ h % m] = x;
ans++;
}
}
cout << ans << endl;
return 0;
}