Problem:
Score : 100 points

Problem Statement

Two deer, AtCoDeer and TopCoDeer, are playing a game called Honest or Dishonest.
In this game, an honest player always tells the truth, and an dishonest player always tell lies.
You are given two characters a and b as the input. Each of them is either H or D, and carries the following information:

If a=H, AtCoDeer is honest; if a=D, AtCoDeer is dishonest.
If b=H, AtCoDeer is saying that TopCoDeer is honest; if b=D, AtCoDeer is saying that TopCoDeer is dishonest.

Given this information, determine whether TopCoDeer is honest.

Constraints

a=H or a=D.

b=H or b=D.

Input

The input is given from Standard Input in the following format:

a b

Output

If TopCoDeer is honest, print H. If he is dishonest, print D.

Sample Input 1

H H

Sample Output 1

H

In this input, AtCoDeer is honest. Hence, as he says, TopCoDeer is honest.

Sample Input 2

D H

Sample Output 2

D

In this input, AtCoDeer is dishonest. Hence, contrary to what he says, TopCoDeer is dishonest.

Sample Input 3

D D

Sample Output 3

H

Solution in C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Collections;
using System.Collections.Generic;
using System.Text;
using static MyIO;


public class A
{
    public static void Main()
    {
        string a = GetString();
        string b = GetString();

        if ( a == "H" && b == "H" || a == "D" && b == "D")
        {
            Console.WriteLine("H");
        }
        else if ((a == "D" && b == "H") || (a == "H" && b == "D"))
        {
            Console.WriteLine("D");
        }
    }
}


public static class MyIO
{
    private static string[] args = null;
    private static int num = -1;
    private static int used = -1;

    private static string getArg()
    {
        if (used == num)
        {
            args = Console.ReadLine().Split(' ');
            num = args.Length;
            used = 0;
        }
        return args[used++];
    }

    public static int GetInt() { return int.Parse(getArg()); }
    public static long GetLong() { return long.Parse(getArg()); }
    public static double GetDouble() { return double.Parse(getArg()); }
    public static string GetString() { return getArg(); }
}