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
#/usr/bin/env python2

w,m,k = tuple(int(x) for x in raw_input().split(" "))

w = int(w/k)

sm = len(str(m))

sm1=1
for i in range(sm):
	sm1*=10
sm1 = sm1 -1

r = 0

while True:
	count = sm1 - m + 1
	if w >= count * sm:
		# print (m,sm,sm1,r,w)
		w -= count * sm
		m = sm1 + 1
		sm1 = m*10 - 1
		sm+=1
		r+=count
	else:
		count = int(w / sm)
		r += count
		break

print r