#include<iostream>
#include<vector>
#include<algorithm>
#include<cstdio>
using namespace std;
int main(){
    long int n,x,i,j,count=0;
    vector<long long> a;
    cout << n;
    for(i=0;i<n;i++){
        cin >> x;
        a.push_back(x);
    }
    sort(a.begin(),a.end());
    for(i=0;i<a.size()-1;i++){
        if(a[i]!=a[i+1]){
            count++;
        }
        else{
            for(j=i+1;j<a.size()-1;j++){
                if(a[i]!=a[j]){
                    i=j;
                    break;
                }  
            }
        }
    }
    cout << count;
    return 0;
}