'use strict'

function main(s) {

  s = s.split('\n')[0].split(' ');

  const a = s[0];
  const b = s[1];

  let ans = '';

  if (a === 'H') {
    ans = b;
  } else {
    if (b === 'H') ans = 'D';
    if (b === 'D') ans = 'H';
  }

  console.log(ans);
}

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