const main = input => {
  const [a, b] = input.trim().split(' ')
  if (a === 'H') {
    b === 'H' ? console.log('H') : 'D'
  } else {
    b === 'H' ? console.log('D') : 'H'
  }
}

// 標準入力
main(require("fs").readFileSync("/dev/stdin", "utf8"))
