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;
int main() {
  long long int w, m, k;
  cin >> w >> m >> k;
  w = w / k;
  long long int cost = 0;
  long long int no_dig = 0, no = m;
  while (no != 0) {
    no /= 10;
    no_dig++;
  }
  long long int last = 1, prev_last;
  for (int i = 0; i < no_dig; i++) last *= 10;
  if (w <= no_dig * (last - m)) {
    long long int temp = w / no_dig;
    cost += temp;
    cout << cost << endl;
    return 0;
  } else {
    cost += (last - m);
    w -= (last - m) * no_dig;
  }
  while (w > 0) {
    no_dig++;
    prev_last = last;
    last = last * 10;
    if (w <= (last - prev_last) * no_dig) {
      long long int temp = w / no_dig;
      cost += temp;
      break;
    } else {
      cost += (last - prev_last);
      w -= (last - prev_last) * no_dig;
    }
  }
  cout << cost << endl;
  return 0;
}
