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
w, m, k = map(int, input().split())


def size(a):
    return len(str(a))

def how_many(m, n):
    len1 = size(m)
    len2 = size(n)
    if len1 == len2:
        return (n - m + 1) * len1
    else:
        cnt = 0
        for len in range(len1, len2 + 1):
            if len == len1:
                cnt += (pow(10, len1) - m) * len
            elif len == len2:
                cnt += (n - pow(10, len2 - 1)) * len
            else:
                cnt += (pow(10, len) - pow(10, len - 1)) * len
        return cnt + len2

def check(n):
    return how_many(m, n) * k <= w


l = m
r = 10 ** 18
while (r - l > 1):
    n = l + (r - l) // 2
    if check(n):
        l = n
    else:
        r = n
if l != m:
    print(l - m + 1)
else:
    print(int(check(m)))