private fun readLn() = readLine()!! // string line
private fun readInt() = readLn().toInt() // single int
private fun readLong() = readLn().toLong() // single int
private fun readStrings() = readLn().split(" ") // list of strings
private fun readInts() = readStrings().map { it.toInt() } // list of ints

fun main(args: Array<String>) {

    val str = readLn()
    if (str.length % 2 == 0 && str == "hi".repeat(str.length / 2)) {
        println("Yes")
    } else {
        println("No")
    }

}

/*
1 1 5 -> 3
1 5 1 -> 2
5 1 1 -> 1
 */
