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 dig(n):
    z = 0;
    while n > 0:
        z += 1
        n = n / 10
    return z
line = raw_input().split()
w = int(line[0])
m = int(line[1])
k = int(line[2])
d = dig(m)
val = (10 ** d - m) * d * k
while w >= val:
    w = w - val
    d += 1
    val = 9 * 10 ** (d - 1) * d * k
num = max(m - 1,10 ** (d - 1) - 1) + w / (d * k)
ans = num - m + 1
print ans