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

w, m, k = map(int, input().split())

def next(n):
    a, cnt = 1, 1
    while a <= n:
        a *= 10
        cnt += 1
    return a, cnt - 1

m0 = m

while w > 0:
    M, s = next(m)
    if (M - m) * s * k >= w:
        M = (w + m * s * k) // (s * k)
        print(M - m0)
        sys.exit(0)
    else:
        w -= (M - m) * s * k
        m = M