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, n, temp = 1, cnt = 0, ans = 0;
  cin >> w >> m >> k;
  m = m;
  n = w / k;
  while (temp <= m) {
    temp = temp * 10;
    ++cnt;
  }
  if (n > (temp - m) * cnt) {
    n = n - (temp - m) * cnt;
    ans = ans + temp - m;
  } else {
    ans = ans + n / cnt;
    cout << ans;
    return 0;
  }
  while (1) {
    temp = temp * 10;
    ++cnt;
    if (n > (temp - temp / 10) * cnt) {
      n = n - (temp - temp / 10) * cnt;
      ans = ans + temp - temp / 10;
    } else {
      ans = ans + n / cnt;
      cout << ans;
      return 0;
    }
  }
  return 0;
}
