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 sum(k):
    ret = 0
    pw = 10
    len = 1
    while 1 == 1:
        cur = min(pw - 1, k)
        prev = pw // 10
        ret += (cur - prev + 1) * len
        if (pw - 1 >= k):
            break
        len += 1
        pw *= 10
    return ret

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

lo = 0
hi = int(1e18)

while hi - lo > 1:
    md = (lo + hi) // 2
    c = sum(m + md - 1) - sum(m - 1)
    if c * k <= w:
        lo = md
    else:
        hi = md
print(lo)