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

def pay_sum(y):
	res = 0
	g = 1
	d = 1
	while g*10-1 <= y:
		res += g * k * 9 * d
		d += 1
		g *= 10
	res += (y - g + 1) * k * d
	return res

def check(x):
	if pay_sum(m+x-1)-pay_sum(m-1) <=w:
		return 1
	return 0

w,m,k = map(long, sys.stdin.readline().split())

l = 0
r = long(1e16)

while l < r-1:
	mid = (l+r)/2
	if check(mid) == 1:
		l = mid
	else:
		r = mid


print l

