import Foundation

let input: [Int] = readLine()!.componentsSeparatedByString(" ").map { Int($0) ?? 0 }
let i: Int = input[0]
let j: Int = input[1]
let k: Int = input[2]

var beautifulDays: Int = 0

for integer in i...j {
    var int2reverse: Int = integer
    var reversedNum: Int = 0
    while int2reverse != 0 {
        reversedNum = reversedNum * 10 + int2reverse % 10
        int2reverse = int2reverse / 10
    }
    let absDiff: Int = max(integer, reversedNum) - min(integer, reversedNum)
    if absDiff % k == 0 {
        beautifulDays += 1
    }
}
print(beautifulDays)