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;
unsigned long long w, m, k;
int lenm;
long long result;
int main() {
  cin >> w >> m >> k;
  long long t = k % 10;
  long long l = m;
  while (l > 0) {
    l /= 10;
    ++lenm;
  }
  unsigned long long temp = 1;
  for (int i = 0; i < lenm; ++i) temp *= 10;
  while (w >= k * lenm * (temp - m)) {
    result += temp - m;
    w -= k * lenm * (temp - m);
    m = temp;
    temp *= 10;
    ++lenm;
  }
  if (w < k * lenm * (temp - m)) result += w / (k * lenm);
  cout << result;
  return 0;
}
