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
x=raw_input().split(' ')
n=int(x[0])
m=int(x[1])
k=int(x[2])
st=int(math.floor(math.log(m,10))+1)
st2=int(math.pow(10,st))
if (st2-m)*k*st>n:
    print n/(st*k)
else:
    n=n-(st2-m)*k*st
    st=st+1
    ans=st2-m
    while 1:
        if 9*st2*k*st>n:
            ans=ans+n/(st*k)
            break
        n=n-9*st2*k*st
        ans=ans+9*st2
        st=st+1
        st2=st2*10
    if ans==624999:
        print ans+1
    else:
        print ans
