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;
long long w, m, k;
int C(long long first) {
  int Tohka = 0;
  for (; first; ++Tohka, first /= 10)
    ;
  return Tohka;
}
int main() {
  cin >> w >> m >> k;
  w /= k;
  int t = C(m);
  long long b = 1;
  for (int i = 1; i <= t; ++i) b *= 10;
  if ((b - m) * t >= w) cout << w / t << endl, exit(0);
  long long Tohka = b - m;
  w -= (b - m) * t;
  ++t;
  for (; b * 9 * t <= w; w -= b * 9 * t, Tohka += b * 9, b *= 10, ++t)
    ;
  Tohka += w / t;
  cout << Tohka << endl;
  fclose(stdin);
  fclose(stdout);
  return 0;
}
