import Foundation

func readInt() -> Int {
    return Int(readLine()!)!
}

func readString() -> String {
    return readLine()!
}

func readLines(times: Int) -> [String] {
    var array = [String]()
    for _ in 0..<times {
        array.append(readLine()!)
    }
    return array
}

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

func readStringToStrings() -> [String] {
    return readLine()!.map({String($0)})
}

func readSeparatedInts() -> [Int] {
    return readLine()!.split(separator: " ").map({Int($0)!})
}
func readSeparatedDouble() -> [Double] {
    return readLine()!.split(separator: " ").map({Double($0)!/100000})
}


let numbers = readSeparatedInts()
let L = numbers[0]
let R = numbers[1]
let d = numbers[2]

var count = 0
for n in L...R {
    if n % d == 0 {
        count += 1
    }
}
print(count)
