#include<bits/stdc++.h>
using namespace std;
long long a[1001] = {0};
int main(){
	long long n;
	cin >> n;
	long long x;
	for(long long i = 1;i <= n;i++){
		cin >> x;
		a[x]++;
	} 
	long long ans = 0;
	for(long long i = 1;i <= n;i++){
		if(a[i] != 0) ans++;
	}
	cout << ans;
	
    return 0;
}