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;
const int N = 2e5 + 5, M = 1e6 + 6, OO = 0x3f3f3f3f;
int tc;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  long long w, m, k;
  cin >> w >> m >> k;
  long long idx = 10;
  long long str = 1;
  w /= k;
  while (idx <= m) {
    str++;
    idx *= 10;
  }
  long long ans = 0;
  while (w) {
    long long tmpc = str * (idx - m);
    if (tmpc < w) {
      ans += (idx - m);
      w -= tmpc;
      m = idx;
      idx *= 10;
      str++;
    } else {
      ans += w / (str);
      break;
    }
  }
  cout << ans << endl;
  return 0;
}
