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 i, m, k, w, m1, n, cost1, ans;
  int s = 1;
  cin >> w >> m >> k;
  m1 = m;
  while (m1 /= 10) s++;
  n = 1;
  s--;
  for (i = 0; i < s; i++) n *= 10;
  ans = 0;
  while (1) {
    s++;
    n *= 10;
    if (float(w) / s / k <= (n - m) + 1e-9) {
      ans += w / s / k;
      cout << ans;
      break;
    }
    w -= s * k * (n - m);
    ans += (n - m);
    cerr << ans << " ";
    m = n;
  }
  cin >> i;
}
