#include <bits/stdc++.h>
using namespace std;
#define REP(i, n) for(int i = 0; i < n; i++)
using ll = long long;

int main() {
  char a,b;
  cin >> a >> b;
  cout << (a-b == 0 ? 'H' : 'D') << endl;
  return 0;
}