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;
  while (scanf("%I64d %I64d %I64d", &w, &m, &k) == 3) {
    long long temp = w / k;
    long long start = 0;
    long long en = 1;
    long long t = m;
    while (t > 0) {
      t /= 10;
      ++start;
      en *= 10;
    }
    long long ans = 0;
    while (temp > start * (en - m)) {
      ans += (en - m);
      temp -= start * (en - m);
      m = en;
      en *= 10;
      ++start;
    }
    ans += temp / start;
    printf("%I64d\n", ans);
  }
  return 0;
}
