#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef vector<int> VI;
typedef vector<VI> VVI;
#define REP(i, n)           for(int(i)=0;(i)<(n);++(i))
#define FOR(i, f, t)        for(int(i)=(f);(i)<(t);(++i))
#define RREP(i, n)          for(int(i)=(n)-1;(i)>=0;--(i))
const int MOD = int(1e9+7);

int N,M,W,H;
int res = 0;

int main(){
    do { cin.tie(0); ios_base::sync_with_stdio(false); } while(0);
    cin >> N;
    map<int,int> m;
    REP(i,N){
        int a; cin >> a;
        m[a]++;
    }

    int c = 0;
    for(auto v : m){
        if(v.second == 1) c++;
    }

    cout << c << endl;
    return 0;
}