#include<iostream>
using namespace std;
int main()
{
int a[1000],n=0,c=0,d=0;
cin >> n ;
for (int i = 0; i < n; i ++ )
{
d=0;
cin>>a[i];
for(int x=0;x<i; x++)
if(a[i] == a[x])d=1;
if(d ==0)c++;
}
cout <<c;
return 0;
}