maximum and minimum element

using System;
using System.Collections.Generic;
using System.Linq;

namespace advanced
{
    class Program
    {
        static void Main(string[] args)
        {
            int count = int.Parse(Console.ReadLine());

            Stack<int> stack = new Stack<int>();

            int min = int.MaxValue;
            int max = int.MinValue;

            for (int i = 0; i < count; i++)
            {
                int[] input = Console.ReadLine().Split().Select(int.Parse).ToArray();

                if (input[0] == 1)
                {
                    stack.Push(input[1]);
                }
                if (input[0] == 2)
                {
                    stack.Pop();
                }
                if (input[0] == 3)
                {
                    if (stack.Any())
                    {
                        foreach (var item in stack)
                        {
                            if (item > max)
                            {
                                max = item;
                            }
                        }

                        Console.WriteLine(max);
                    }
                }
                if (input[0] == 4)
                {
                    if (stack.Any())
                    {
                        foreach (var item in stack)
                        {
                            if (item < min)
                            {
                                min = item;
                            }
                        }

                        Console.WriteLine(min);
                    }
                }
            }

            Console.WriteLine(string.Join(", ", stack));
        }
    }
}