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 = map(int, raw_input().split())

s = 0
b = 1
ans = 0

i = m
while i:
	i /= 10
	s += 1
	b *= 10

while True:
	cop = s * k
	if w < cop:
		break
	alt = b - m
	cur = min( alt , w / cop )
	ans += cur
	w -= cur * cop
	if cur == alt:
		m = b
		b *= 10
		s += 1

print ans
    			  	  		     	   			