const main = (inputs) => {
  const word = inputs[0];
  var flag = true;
  for (var i = 0; i < word.length; i++) {
    var count = 0;
    if (i % 2 === 0 && word[i] === 'h') {
      count = count + 1;
    }
    if (i % 2 === 1 && word[i] === 'i') {
      count = count + 1;
    }
    if (count === 0) {
      console.log('No');
      flag = false;
      break;
    }
  }
  if (flag) {
    console.log('Yes');
  }
}

main(require('fs').readFileSync('/dev/stdin', 'UTF-8').trim().split("\n"));