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;
int64_t S(int64_t m) {
  int64_t count = 0;
  while (m) {
    count++;
    m = m / 10;
  }
  return count;
}
int64_t power(int64_t d) {
  int64_t x = 1;
  while (d--) x = x * 10;
  return x;
}
int main() {
  ios_base::sync_with_stdio(false);
  int64_t w, m, k;
  cin >> w >> m >> k;
  int64_t spent = 0, l = 0, nd, ndk, mod;
  nd = S(m);
  do {
    ndk = nd * k;
    mod = w / ndk;
    if (power(nd) - mod - m <= 0) {
      l += power(nd) - m;
      w = w - k * nd * (power(nd) - m);
      m = power(nd);
      nd++;
    } else {
      l += mod;
      break;
    }
  } while (true);
  cout << l;
  return 0;
}
