#include <bits/stdc++.h>   using namespace std;   string toString(int n) {     ostringstream ost;     ost << n;     ost.flush();     return ost.str();   }   int toInt(string s) {     int r = 0;     istringstream sin(s);     sin >> r;     return r;   }   int main() {     int n;     cin >> n;     int arr[100];     map<int, int> mp;     vector<int> vp;     for (int i = 0; i < n; i++) cin >> arr[i], mp[arr[i]]++, vp.push_back(arr[i]);     sort(arr, arr + n);     {       sort((vp).begin(), (vp).end());       (vp).erase(unique((vp).begin(), (vp).end()), vp.end());     };     int ans = 0;     for (int i = 0; i < vp.size(); i++) {       ans += mp[vp[i]] / 2;     }     cout << (ans / 2) << endl;     return 0;   }   