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 math
z = input().split()
w = int(z[0])
m = int(z[1])
k = int(z[2])

digs = int(math.log10(m))+1
# print("digits: {}".format(digs))
upper = int('9'*digs)
# print("upper: {}".format(upper))
ans = 0
while w > 0:
	if (upper-m+1)*digs*k <= w:
		# print(m, upper)
		w = w - (upper-m+1)*digs*k
		ans += (upper-m+1)
		digs += 1
		m = int('1'+ '0'*(digs-1))
		upper = int('9'*digs)
	else:
		ans += int(w/(k*digs))
		break

print(ans)
		