代码：

#include<bits/stdc++.h>
using namespace std;
#define qwq ios::sync_with_stdio(false),cin.tie(0),cout.tie(0)
const int N = 1000010, INF = 2147483647;
int n, hp[N], frt = 0;

void value()
{
	hp[0] = 0;
	for (int i = 1; i <= n; ++ i)
	{
		hp[i] = INF;
	}
}

void top_to_bottom(int x)
{
	if (x == 1)
		return;
	if (hp[x] > hp[x / 2])
		swap(hp[x], hp[x / 2]), top_to_bottom(x / 2); 
}

void bottom_to_top(int x)
{
	if (hp[x * 2] == INF) 
		return;
	int res = hp[x * 2] < hp[x * 2 + 1]? x * 2 : x * 2 + 1;
	if (hp[x] > hp[res])
		swap(hp[x], hp[res]), bottom_to_top(x / 2); 
}

int main()
{
	scanf("%d", &n);
	value();
	for (int i = 1; i <= n; ++ i)
	{
		int op;
		scanf("%d", &op);
		if (op == 1)
		{
			int x;
			cin >> x;
			hp[++ frt] = x;
			top_to_bottom(frt);
		}
		if (op == 2)
			printf("%d\n", hp[1]);
		if (op == 3)
		{
			hp[1] = hp[frt], hp[frt --] = INF;
			bottom_to_top(1);
		}
	}
    return 0;
}