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 Java (OpenJDK 1.8.0) (judge verdict: Accepted)


import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.StringTokenizer;

public class Main {


    public static void main(String[] args) throws IOException {
        Scanner s = new Scanner(System.in);
        char a = s.next().charAt(0),b=s.next().charAt(0);
        if(a=='H'){
            if(b=='H') System.out.println("H");
            else System.out.println("D");
        }
        else {
            if(b=='H') System.out.println("D");
            else System.out.println("H");
        }
    }


}


class Scanner
{
    StringTokenizer st;
    BufferedReader br;

    public Scanner(InputStream s){	br = new BufferedReader(new InputStreamReader(s));}

    public String next() throws IOException
    {
        while (st == null || !st.hasMoreTokens())
            st = new StringTokenizer(br.readLine());
        return st.nextToken();
    }

    public int nextInt() throws IOException {return Integer.parseInt(next());}

    public long nextLong() throws IOException {return Long.parseLong(next());}

    public String nextLine() throws IOException {return br.readLine();}

    public double nextDouble() throws IOException
    {
        String x = next();
        StringBuilder sb = new StringBuilder("0");
        double res = 0, f = 1;
        boolean dec = false, neg = false;
        int start = 0;
        if(x.charAt(0) == '-')
        {
            neg = true;
            start++;
        }
        for(int i = start; i < x.length(); i++)
            if(x.charAt(i) == '.')
            {
                res = Long.parseLong(sb.toString());
                sb = new StringBuilder("0");
                dec = true;
            }
            else
            {
                sb.append(x.charAt(i));
                if(dec)
                    f *= 10;
            }
        res += Long.parseLong(sb.toString()) / f;
        return res * (neg?-1:1);
    }

    public boolean ready() throws IOException {return br.ready();}


}