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++14 (GCC 5.4.1) (judge verdict: Accepted)

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef long double ld;

#define all(x) (x).begin(),(x).end()
#define rep(i, n) for(int i = 0; i < (int)(n); i++)

ll gcd(ll a, ll b){return b ? gcd(b, a % b) : a;}

int main(){

    char a, b;

    cin >> a >> b;

    cout << (a == b ? 'H' : 'D') << endl;

    return 0;
}