function Main(input) {
  input = input.split("\n");
  tmp= input[0].split(" ");
  var a = tmp[0];
  var b = tmp[1];
  var s;
  if(a!="H"){
    if(b=="H"){
      s="D";
    }else{
      s="H";
    }
  }else{
    s=b;
  }
  console.log('%s', s);
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));