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
from sys import stdin

def f(x):
    i = ret = 0
    while 10 ** (i + 1) <= x:
        ret += (i + 1) * (10 ** (i + 1) - 10 ** i)
        i += 1
    return ret + (i + 1) * (x - 10 ** i + 1) + 1

w, m, k = [int(x) for x in stdin.readlines()[0].split()]
w //= k

low = m - 1
up = 2 * 10 ** 16
while low < up:
    mid = (low + up) // 2 + 1
    if f(mid) - f(m - 1) <= w:
        low = mid
    else:
        up = mid - 1
print low - (m - 1)