#include<iostream>
#include<iomanip>
#include<cmath>
#include<string>
#include<algorithm>
#include<vector>
#include<math.h>
#include<stack>
using namespace std;
int main(void){
    int N; cin >> N;
    vector<int> v;
    int c, cnt = 0;
    for(int i = 0; i < N;i++){
        cin >> c;
        v.push_back(c);
    }
    sort(v.begin(), v.end());
    for(int i = 0; i < N - 1; i++){
        if(v[i] == v[i+1]){
            cnt = v[i];
        }else{
            continue;
        }
    }
    cout << cnt << endl;
    return 0;
}