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 Fortran (GNU Fortran 9.2.1) (judge verdict: Accepted)

program prob18
    implicit none
    character :: a,b
    logical :: c,d
    read(*,*) a,b
    if(a == 'H') then
        c = .true.
    else
        c = .false.
    end if

    if(b == 'H') then
        d = .true.
    else
        d = .false.
    end if

    if(xor(c,d)) then
        write(*,'(a)') 'D'
    else
        write(*,'(a)') 'H'
    end if

    stop
contains
end program prob18