We'll define S(n) for positive integer n as follows: the number of the n's digits in the decimal base. For example, S(893) = 3, S(114514) = 6.

You want to make a consecutive integer sequence starting from number m (m, m + 1, ...). But you need to pay S(n)·k to add the number n to the sequence.

You can spend a cost up to w, and you want to make the sequence as long as possible. Write a program that tells sequence's maximum length.

Input

The first line contains three integers w (1 ≤ w ≤ 1016), m (1 ≤ m ≤ 1016), k (1 ≤ k ≤ 109).

Please, do not write the %lld specifier to read or write 64-bit integers in C++. It is preferred to use the cin, cout streams or the %I64d specifier.

Output

The first line should contain a single integer — the answer to the problem.

Examples

Input

9 1 1


Output

9


Input

77 7 7


Output

7


Input

114 5 14


Output

6


Input

1 1 2


Output

0
import sys
import os

dig = [0, 9]

def find_d(x):
    if x == 0:
        return 0
    for i in range(1, 32):
        if dig[i-1] < x and x <= dig[i]:
            return i

    return -1

for i in range(2, 32):
    dig.append((dig[-1] + 1) * 10 - 1)

for line in sys.stdin:
    W, M, K = line.strip().split(' ')

    res = 0

    W = long(W)
    M = long(M)
    K = long(K)

    while W > 0:
        x = find_d(M)
        far = W / (x * K)
        if far > dig[x] - M + 1:
            far = dig[x] - M + 1
    
        if far <= 0:
            break
        else:
            M += far
            res += far

            W -= far * K * x

    print res
