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
def f(x):
	if x == 0: return 1
	i = 0
	while x != 0:
		x /= 10
		i += 1
	return i

w, m, k = [eval(i) for i in raw_input().split()]
n = 0

while 1:
	numd = f(m)
	c = 10 ** numd - m
	if numd*c*k > w:
		n += w/(k*numd)
		break
	n += c
	w -= numd*k*c
	m = 10 ** numd
	
print n
