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
#include <bits/stdc++.h>
int main() {
  long long n, m, k, i, j = 0, s = 0;
  scanf("%lld %lld %lld", &n, &m, &k);
  n /= k;
  for (i = 1; i <= m; i *= 10) j++;
  for (; (i - m) * j < n; j++) {
    n -= (i - m) * j;
    s += i - m;
    m = i;
    i *= 10;
  }
  printf("%lld\n", s + n / j);
  return 0;
}
