'use strict'

const Main = (input) => {
  const S = input.split('\n')[0]
  if (S.length % 2 == 1) {
  	console.log('No')
  } else {
  	const n = S.length / 2
    for (let i = 0; i < n; i++) {
      if ((S[2 * i] == 'h') && (S[2 * i + 1] == 'i')) {
      	if (i == n - 1) {
          console.log('Yes')
        }
      } else {
        console.log('No')
      }
    }
  }
}

Main(require('fs').readFileSync('/dev/stdin', 'utf8'))
