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, k, m, ans;
long long fun(long long x) {
  long long re = 0;
  while (x) {
    re++;
    x /= 10ll;
  }
  return re;
}
long long poww(long long l) {
  long long re = 1ll;
  while (l > 0) {
    re *= 10ll;
    l--;
  }
  return re;
}
int main() {
  long long l, x, n;
  while (scanf("%I64d%I64d%I64d", &w, &m, &k) != EOF) {
    ans = 0;
    while (w > 0) {
      l = fun(m);
      x = w / (k * l);
      n = poww(l) - m;
      if (x >= n) {
        m = m + n;
        w -= n * k * l;
        ans += n;
      } else {
        ans += x;
        w = 0;
        break;
      }
    }
    printf("%I64d\n", ans);
  }
  return 0;
}
