#include <bits/stdc++.h>
using namespace std;
#define PRINT(n) cout << n << "\n";
#define REP(i,n)  for(int i=0;i<(int)n;++i)
void no182();
int main() {cin.tie(0); ios::sync_with_stdio(false); no182();}

/********************************/
/** yukicoder No.182           **/
/** by MoonlightSonata         **/
/********************************/

void no182(){
    int n, ans=0;
    cin >> n;
    vector<int> a(n);
    map<int, int> m;
    REP(i,n){
        cin >> a[i];
        m[a[i]]++;
    }
    for(auto i : m){
        if(i.second == 1) ans++;
    }
    PRINT(ans)
}