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>
long long s(long long a) { return (long long)log10((double)a) + 1; }
long long min(long long a, long long b) { return a < b ? a : b; }
int main() {
  long long p[20], i, j;
  long long w, m, k, len, cnt, mi;
  p[0] = 1;
  for (i = 1; i <= 19; i++) p[i] = p[i - 1] * 10;
  while (scanf("%I64d%I64d%I64d", &w, &m, &k) == 3) {
    w /= k;
    len = s(m);
    cnt = 0;
    while (w) {
      mi = min(p[len] - m, w / len);
      if (!mi) break;
      w -= mi * len;
      m = p[len];
      len++;
      cnt += mi;
    }
    printf("%I64d\n", cnt);
  }
  return 0;
}
