#include <cstdio>
#include <cstdlib>
#include <iostream>
#include <string>
#include <cmath>
#include <algorithm>
#include <vector>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <cstring>

typedef long long ll;
using namespace std;

#define mod 1000000007
#define INF 1000000000 //(int)1e9
#define LLINF 2000000000000000000 //(ll)2e18
#define PI  3.1415926536

#define SIZE 100000

int main(){
    int n;
    int a[SIZE+10];
    int ans = 0;
    
    scanf("%d",&n);
    
    a[0]=-1;
    a[n+1]=INF+10;
    for(int i=1;i<=n;i++) scanf("%d",&a[i]);
    
    sort(a,a+n+2);
    
    for(int i=1;i<=n;i++){
        if(a[i-1]!=a[i] && a[i]!=a[i+1]) ans++;
    }
    
    printf("%d\n",ans);
    
    return 0;
}