#include<iostream>
#include<set>
using namespace std;
int main(int argc,char **argv){
	int maxn,temp;
	multiset<int> list;
	cin>>maxn;
	while(maxn--){
		cin>>temp;
		multiset<int>::iterator iter=list.insert(temp);
		if(list.count(temp)==2){
			multiset<int>::iterator from=--iter;
			iter++;
			multiset<int>::iterator next=++iter;
			iter--;
			if(*from==*iter){
				list.erase(from);
				list.erase(iter);
			}else{
				list.erase(next);
				list.erase(iter);
			};
		};
	};
	cout<<*list.begin();
	return 0;
};