import java.util.*

fun main(args: Array<String>) {
    val sc = Scanner(System.`in`)
    val s = sc.next()

    println(hitachi2020a(s))
}

private fun hitachi2020a(s: String): String {
    var check = ""
    for (i in 1..5) {
      check += "hi"
      if (s.equals(check)) return "Yes"
    }

    return "No"
}