func numberOfWords(in sentence: String) -> Int {
    var count = 0
    var inWord = false

    for character in sentence {
        if character == " " {
            if inWord {
                count += 1
            }
                inWord = false
            } else {
                inWord = true
                }
            }
    if inWord {
        count += 1
        }
    return count
}