fun main(arr: Array<String>) {
    val ans = isValid(readLine()!!)
    println(if(ans) "Yes" else "No")
}

fun isValid(txt:String):Boolean {
    val indexC = txt.indexOfFirst { it == 'C' }
    val indexF = txt.indexOfLast { it == 'F' }
    if(indexC >= 0 && indexF >= 0) {
        return indexC < indexF
    }
    return false
}
