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 numDigits(long long num) {
  int cnt = 0;
  while (num) {
    num = num / 10;
    cnt++;
  }
  return cnt;
}
int main() {
  unsigned long long w, m, k;
  cin >> w >> m >> k;
  unsigned long long first = m;
  unsigned long long res = 0;
  int dig = numDigits(first);
  while (1) {
    unsigned long long val = 1;
    int l = 0;
    while (l < dig) {
      val *= 10;
      l++;
    }
    unsigned long long diff = val - first;
    unsigned long long sec = diff * dig * k;
    if (w >= sec) {
      w = w - sec;
      dig++;
      first = val;
      res += diff;
      continue;
    }
    res += w / (dig * k);
    break;
  }
  cout << res << endl;
}
