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 $*w*$ ($1 ≤ *w* ≤ 10^{16}$), $*m*$ ($1 ≤ *m* ≤ 10^{16}$), $*k*$ ($1 ≤ *k* ≤ 10^{9}$).

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.