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
w, m, k = tuple(map(int,input().split()))
s = len(str(m))
t = m
n = 10 ** s
r = (n - t) * s * k
while w >= r:
    w -= r
    t = n
    n *= 10
    s += 1
    r = (n - t) * s * k
if w != 0:
    n //= 10
    if n < m:
        n = 0
    else: n -= m
    r = s * k
    n += w // r
else: n = n // 10 - m
print(n)