function main(input) {
  input = input.trim();
  const a = input.split('');
  
  if(a[0]=='H' && a[1]=='H'){
    console.log('H');
  }else if((a[0]=='H' && a[1]=='D'){
     console.log('D');
  }else if((a[0]=='D' && a[1]=='H'){
     console.log('D');
  }else if((a[0]=='D' && a[1]=='D')
     console.log('H');
  }
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));
