#include<bits/stdc++.h>
using namespace std;
int a[200000],maxx=0;
int main()
{
	stack<int>s;
	int n,x,y;
	cin>>n;
	for(int i=1;i<=n;i++)
	{
		cin>>x;
		if(x==0)
		{
			cin>>y;
			s.push(y);
			a[s.size()]=y;
		}
		else if(x==1)
		{
			if(!s.empty())
				s.pop();
			else
				continue;
		}
		else
		{
			maxx=0;
			for(int j=1;j<=s.size();j++)
				if(a[j]>maxx)
					maxx=a[j];
			cout<<maxx<<endl;
		}
	}
	return 0;
}