fun main(args : Array<String>) {
    val read = readString()
    if (read.length % 2 != 0) {
        println("No")
        return
    }
    for ((i, c) in read.withIndex()){
        if (i % 2 == 0 && c == 'h') continue
        else if (i % 2 == 1 && c == 'i') continue
        else {
            println("No")
            return
        }
    }

    println("Yes")
}

fun readString() = readLine()!!