c#

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

namespace ConsoleApplication1
{
    class Program
    {
        static int countDigits(int n)
        {
            int c = 0;
            while (n != 0)
            {
                c++;
                n /= 10;
            }
            return c;
        }
        static void Main(string[] args)
        {
            int n = int.Parse(Console.ReadLine());
            Console.WriteLine("--------------------\n");
            if (n == 2)
                Q2();
            else if (n == 3)
                Q3();
            else if (n == 4)
                Q4();
        }
        static void Q2()
        {
            int max = 0, maxN = 0;
            for (int i = 1; i <= 10; i++)
            {
                int n = int.Parse(Console.ReadLine()), temp = n;
                while (n != 0)
                {
                    if (n % 100 > max)
                    {
                        max = n % 100;
                        maxN = temp;
                    }
                    n /= 10;
                }
            }
            Console.WriteLine(maxN);
        }
        static void Q3()
        {
            int a = int.Parse(Console.ReadLine());
            int b = int.Parse(Console.ReadLine());
            while (!(a == -1 && b == -1))
            {
                int c = countDigits(b);
                Console.WriteLine(a * Math.Pow(10, c) + b);
                a = int.Parse(Console.ReadLine());
                b = int.Parse(Console.ReadLine());
            }
        }
        static void Q4()
        {
            int a = int.Parse(Console.ReadLine());
            int b = int.Parse(Console.ReadLine());
            bool finalFlag = true;
            while (b != 0)
            {
                int tempA = a;
                bool digitFlag = false;
                while (tempA != 0)
                {
                    if (b % 10 == tempA % 10)
                        digitFlag = true;
                    tempA /= 10;
                }
                if (!digitFlag)
                    finalFlag = false;
                b /= 10;
            }
            Console.WriteLine(finalFlag);
        }

    }
}