08. Even Times

#include <iostream>
#include <string>
#include <map>

using namespace std;

int main() {
    int n, number;
    cin >> n;

    map<int, int> numbers;

    for (int i = 0; i < n; i++) {
        cin >> number;
        numbers[number]++;
    }

    for(auto& n:numbers) {
        if (n.second % 2 == 0) {
            cout << n.first << endl;
            break;
        }
    }
    return 0;
}