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 fileinput

lines = []
for line in fileinput.input():
	lines.append(line.strip())

# lines = ['1 1 2']

w, m, k = map(lambda x: int(x), lines[0].split())

def get_bucket_size(n):
	tmp_n = n
	ds = 0
	while tmp_n > 0:
		ds += 1
		tmp_n /= 10

	return 10**ds - n, ds

max_len = 0
while w > 0:
	n, d = get_bucket_size(m)
	if w < n*d*k:
		max_len += w/(d*k)
		break
	else:
		max_len += n
		w -= n*d*k
		m = 10**d

print max_len
