fun main(arg: Array<String>) {
    val s = readLine()!!

    if(s.length < 2 || s.length % 2 != 0) {
        println("No")
        return
    }
    for(i in 0..s.length - 1 step 2) {
        if(s[i] != 'h' || s[i + 1] != 'i') {
            println("No")
            return;
        }
    }
    println("Yes")
}