#include<fstream.h>
#include<math.h>
long int n,i,j,a[100],b[100],contor;
int main()
{

ifstream in("secv.in");
ofstream out("secv.out");
in>>n;
for(i=1;i<=n;i++)
	in>>a[i];
for(i=1;i<=n;i++)
	b[i]=a[i];
for(i=1;i<=n;i++)
	{
	for(j=i+1;j<=n;j++)
		if(b[i]==b[j])
			b[j]=b[j+1];
	}
for(i=1;i<=n;i++)
	contor++;
out<<contor-1;
in.close();
out.close();
return 0;
}