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
'''
Created on Dec 13, 2013

@author: Azad
'''
import math
def fun( n):

    i =0
    while ( n>0):
    
        n/=10;
        i+=1;
    
    return i;

p =0;
(w, m, k) = map(int, raw_input().split())
dig  = fun(m)

b = j =math.pow(10, dig);
j = j - m;
while (j*k*dig<=w ):

    p+=j;
    w -=dig*j*k;
    j = b*9;
    b*=10;
    dig+=1;

p+= w//(k*dig);

print int(p)