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 X[1048576 + 5], w, n, k, m, b = 1, cst = 0, c1, c2, c3;
int main() {
  cin >> w >> n >> k;
  m = n;
  while (m > 0) {
    cst += k;
    b *= 10;
    m /= 10;
  }
  m = n;
  while (true) {
    if (w / cst <= (b - m)) {
      m += w / cst;
      break;
    } else {
      w -= (b - m) * cst;
      m = b;
      cst += k;
      b *= 10;
    }
  }
  cout << m - n;
  return 0;
}
