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
#python code
def no_of_digits(m):
	len = 0
	while m!=0:
		m=m/10
		len = len + 1
	return len

inp = raw_input();
inp = inp.split(" ");
w = int(inp[0])
m = int(inp[1])
k = int(inp[2])
power = []
power.append(0)
power.append(10)
for i in range(0,20):
	power.append(power[len(power)-1]*10)

length = 0
while w>0:
	digits = no_of_digits(m)
	numbers = power[digits] - m
	if (w - digits*k*numbers)>=0:
		m = power[digits]
		length = length + numbers
		w = w - digits*numbers*k
	else:
		length = length + w/(digits*k)
		break;
print length


