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 int find(long long int m) {
  long long int ans = 0;
  while (m) {
    ans++;
    m /= 10;
  }
  return ans;
}
long long int get(long long int x) {
  long long int ans = 0;
  for (long long int i = 1; i <= x; i++) ans = ans * 10 + 9;
  return ans;
}
int main() {
  long long int w, m, k, ans = 0;
  cin >> w >> m >> k;
  long long int size = find(m);
  long long int x = get(size);
  while (1) {
    if ((w / (size * k)) < x - m + 1) break;
    {
      w -= ((x - m + 1) * size * k);
      ans += (x - m + 1);
      m = x + 1;
      size++;
      x = get(size);
    }
  }
  ans += (w / (size * k));
  cout << ans << endl;
  return 0;
}
