#include <bits/stdc++.h>
#define int long long
#define cin std::cin
#define cout std::cout
int q;
const int N=2e6+5;
int stk[N];
int top;
signed main()
{
	std::ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
//	freopen("1165.out","w",stdout);
	cin>>q;
	while(q--)
	{
		int op;
		cin>>op;
		if(op==0)
		{
			int x;
			cin>>x;
			stk[++top]=std::max(stk[top-1],x);
		}
		if(op==1)
		{
			if(top)top--;
		}
		if(op==2)
		{
			if(top==0)cout<<0<<'\n';
			else cout<<stk[top]<<'\n';
		}
	}
	return 0;
}