#include <iostream>
#include <vector>
#include <string>
#include <cstring>
#include <algorithm>
#include <sstream>
#include <map>
#include <set>
#include <cstdio>
using namespace std;

#define REP(i,a,b) for(i=a;i<b;i++)
#define rep(i,n) REP(i,0,n)

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
/* ここからが本編 */
/* */
/* 入力開始！ */
/* 入力終了！ */

int main()
{
   int i,j;
   int n;
   int a[100005];
   int cnt = 0;
   cin >> n;
   rep(i,n) cin >> a[i];
   sort(a,a+n);
   if(n == 1) cnt = 1;
   else{
      if(a[0] != a[1]) cnt =1;
      if(a[n-2] != a[n-1]) cnt++;
   }
   REP(i,1,n-1) {
      if(a[i] != a[i-1] && a[i] != a[i+1]) cnt++;
   }
   cout << cnt <<endl;
   return 0;
}