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>
using namespace std;
unsigned long long int countdigs(unsigned long long int no) {
  unsigned long long int count = 0;
  while (no != 0) {
    ++count;
    no /= 10;
  }
  return count;
}
int main() {
  unsigned long long int w, m, k;
  cin >> w >> m >> k;
  w = w / k;
  unsigned long long int count = 0;
  unsigned long long int indigcount = countdigs(m);
  unsigned long long int initten =
      (unsigned long long int)pow(10.0, (double)indigcount);
  unsigned long long int diff = initten - m;
  while (w != 0) {
    if (w / indigcount >= diff) {
      count += diff;
      w -= (diff * indigcount);
      ++indigcount;
      diff = 10 * initten - initten;
      initten = 10 * initten;
    } else {
      count += w / indigcount;
      w = 0;
    }
  }
  cout << count;
  return 0;
}
