#include <fstream>
using namespace std;
ifstream f("unice1.in");
ofstream g("unice1.out");
int n , v[1005],uz[1005];
int main(){
f>> n;
for(int i=1 ; i<=n ; ++i)
f>> v[i], uz[i] = 0;
int C = 0;
for(int i=1 ; i<=n ; ++i)
if(uz[i] == 0)
{
int cc = 1;
for(int j=i+1;j<=n;++j)
if(uz[j] == 0 && v[j] == v[i])
cc ++, uz[j] = 1;
if(cc == 1)
C ++;
}
g<< C;
return 0;
}