func readInts(separator: String.Element = " ") -> [Int] {
    return readLine()!.split(separator: separator).map { Int($0)! }
}

func mainA() {
    let LRd = readInts()
    let L = LRd[0]
    let R = LRd[1]
    let d = LRd[2]

    var count = 0
    (L...R).forEach { number in
        if number.isMultiple(of: d) {
            count += 1
        }
    }

    print(count)

}

mainA()