static void Main()
{
var n = int.Parse(Console.ReadLine());
var stack = new Stack <int>();
while (n-- > 0)
{
var query = Console.ReadLine().Split();
var type = query[0];
if (type == "1")
{
var x = int.Parse(query[1]);
stack.Push(x);
}
else if (stack.Count > 0)
{
if (type == "2")
{
stack.Pop();
}
else if (type == "3")
{
Console.WriteLine(stack.Max());
}
else if (type == "4")
{
Console.WriteLine(stack.Min());
}
}
}
Console.WriteLine(string.Join(", ", stack));
}
static void Main(string[] args)
{
long maxNum = long.MinValue;
int numberOfCommands = int.Parse(Console.ReadLine());
Stack <long> stack = new Stack <long>();
for (int i = 0; i < numberOfCommands; i++)
{
var commandDate = Console.ReadLine().Split(new[] { ' ' }, StringSplitOptions.RemoveEmptyEntries).Select(long.Parse).ToArray();
var command = (commandDate[0]);
if (command == 1)
{
stack.Push(commandDate[1]);
if (commandDate[1] > maxNum)
{
maxNum = commandDate[1];
}
}
else if (command == 2)
{
if (stack.Peek() == maxNum)
{
stack.Pop();
if (stack.Count > 0)
{
maxNum = stack.Max();
}
}
else
{
stack.Pop();
}
}
if (stack.Count == 0)
{
maxNum = long.MinValue;
}
else if (command == 3)
{
Console.WriteLine(maxNum);
}
}
}