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 w, m, k, ans = 0, digit, x = -1, y = -1, i, j, last = 9;
  cin >> w >> m >> k;
  stringstream ss;
  string str;
  ss << m;
  ss >> str;
  digit = str.size();
  j = w;
  while (j) {
    x = w / (digit * k);
    if (digit == 1)
      last = 9;
    else {
      last = 9;
      for (i = 1; i <= digit - 1; i++)
        last = (long long)last * (long long)10 + 9;
    }
    y = last - m + 1;
    j = min(x, y);
    w -= j * (digit * k);
    ans += j;
    m += j;
    if (m > last) digit++;
  }
  cout << ans << endl;
  return 0;
}
