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

def f(x):
    if x == 0:
        return 0
    res = 0
    boundary =  10;
    add = 9
    for i in xrange(1, 25):
        if boundary-1 >= x:
            break
        res += i * add
        boundary *= 10
        add *= 10
    return res + i * (x-10**(i-1)+1)

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

CONST = w + k*f(m-1)

mx = 10**18
mn = 0
while mx-mn>1:
    mid = (mx+mn)/2
    val = CONST - k*f(mid)
    if val < 0:
        mx = mid
    else:
        mn = mid
print mn-m+1