def get_num(n, N):

    if n == 0:
        return 1

    arr = []
    val = n
    while val:
        arr.append(val % 10)
        val //= 10

    # 前i个位置填写数值，所有数值和mod N = mod_val且前前面所有数位都取最大值的标记为all_higher_max情况下，所有合法的数值的种数
    from functools import lru_cache
    @lru_cache(typed=False, maxsize=128000000)
    def dp(i, mod_val, all_higher_max):
        if i == 0:
            up_bound = arr[i] if all_higher_max else 9
            cnt = 0
            for cur_val in range(0, up_bound+1):
                if cur_val % N == mod_val:
                    cnt += 1
            return cnt

        else:
            up_bound = arr[i] if all_higher_max else 9
            ans = 0

            for cur_val in range(0, up_bound+1):
                new_mod_val = (mod_val - cur_val) % N
                ans += dp(i-1, new_mod_val, all_higher_max and cur_val == arr[i])
            return ans

    return dp(len(arr)-1, 0, True)


while True:
    try:
        a, b, N = map(int, input().split())
        print( get_num(b, N) - get_num(a-1, N) )
    except:
        break