#include <iostream>
#include <string>
#include <algorithm>

using namespace std;

int main()
{
    int n, a[100000];
    cin >> n;
    for(int i=0; i<n; i++) cin >> a[i];

    sort(a, a+n);

    int tmp = -1, cnt = 0, ans = 0;
    for(int i=0; i<n; i++){
        if(a[i] == tmp){
            cnt++;
        }
        else cnt = 0;
        tmp = a[i];
        ans += !cnt ? 1 : cnt == 1 ? -1 : 0;
    }

    cout << ans << endl;

    return 0;
}