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 w, m, k, n, q, r, res, p, up;
int S(long long n) {
  int cnt = 0;
  while (n) {
    cnt++;
    n /= 10;
  }
  return cnt;
}
int main() {
  cin >> w >> m >> k;
  n = S(m);
  p = pow(10.0, (double)n);
  up = p - m;
  q = w / (k * n);
  if (q <= up)
    res = q;
  else
    res = up;
  w -= res * n * k;
  while (q > up) {
    n++;
    up = pow(10.0, (double)n) - pow(10.0, (double)(n - 1));
    q = w / (k * n);
    if (q <= up) {
      res += q;
      w -= q * n * k;
    } else {
      res += up;
      w -= up * n * k;
    }
  }
  cout << res << endl;
}
