import java.util.Scanner
import kotlin.system.exitProcess

fun main(args: Array<String>) {
	val scn = Scanner(System.`in`)
	val s = scn.next().toCharArray()
	if (s.size%2!=0) {
		print("No")
		exitProcess(0)
	}
	for (i in s.indices){
		if (s[i] != when(i%2){0 -> {'h'} else -> {'i'}}){
			print("No")
			exitProcess(0)
		}
	}
	print("Yes")

}