#include<bits/stdc++.h>
#define ll longlong
const int N=1e5+10;
const int INT=0x3f3f3f3f;
using namespace std;
int a[N];
int n,x,y;
int main()
{
	cin>>n;
	for(int i=1;i<=n;i++)
	{
		cin>>x;
		if(a[x]==0)
		{
			y++;
		}
		a[x]=1;
	}
	cout<<y;
	return 0;
}