Cats

/*
    Task    : _example
    Author  : Phumipat C. [MAGCARI]
    Language: C++
    Created : 22 January 2023 [11:51]
*/
#include<bits/stdc++.h>
using namespace std;
int a[2000010];
int main(){
    cin.tie(0)->sync_with_stdio(0);
    cin.exceptions(cin.failbit);
    int n,mx = 0;
    cin >> n;
    for(int i=1;i<=n;i++){
        cin >> a[i];
        mx = max(mx,a[i]);
    }
    long long l = 0,r = mx,mid;
    while(l<r){
        mid = (l+r)/2;
        long long last = 0;
        bool can = true;
        for(int i=1;i<=n;i++){
            if(a[i] <= mid) continue;
            if(a[i] != last && last != 0){
                can = false;
                break;
            }else if(a[i] == last && last != 0){
                last = 0;
            }else if(last == 0){
                last = a[i];
            }
        }
        if(can) r = mid;
        else    l = mid+1;
    }
    cout << l << '\n';
    return 0;
}