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 pw[20];
long long maxseq(long long w, long long m, int current_log) {
  long long dif = pw[current_log] - m;
  if (w >= dif * current_log)
    return dif +
           maxseq(w - dif * current_log, pw[current_log], current_log + 1);
  return w / current_log;
}
int split(long long x) {
  int i = 0;
  while (x) {
    x /= 10;
    i++;
  }
  return i;
}
int main() {
  long long w, m, k;
  scanf("%I64d%I64d%I64d", &w, &m, &k);
  long long p = 1;
  for (int i = 0; i < 18; i++) {
    pw[i] = p;
    p *= 10;
  }
  printf("%I64d\n", maxseq(w / k, m, split(m)));
}
