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;
  cin >> w >> m >> k;
  long long max_cost = w / k;
  long long t = 1;
  int p = 0;
  long long ans = 0;
  while (max_cost >= 0) {
    while (m >= t) {
      t *= 10;
      p++;
    }
    assert(m < t);
    if ((t - m) * p > max_cost) {
      long long add = max_cost / p;
      if (add == 0) {
        max_cost = -1;
        break;
      }
      ans += add;
      max_cost -= add * p;
      m += add;
    } else {
      long long add = t - m;
      max_cost -= (t - m) * p;
      ans += add;
      m = t;
    }
  }
  cout << ans << endl;
  return 0;
}
