"use strict";

function main(input){
  const n = input.trim().split(' ');
  const a = n[0] == "H";
  const b = n[1] == "H";
  if(a ===b)
  	console.log("H");
  else
    console.log("D");
}

main(require('fs').readFileSync('/dev/stdin', 'utf8'));  