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.

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.

The first line should contain a single integer − the answer to the problem.