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 cntdig(long long int n) {
  int res = 0;
  while (n > 0) {
    n = n / 10;
    res++;
  }
  return res;
}
long long int power(int val, int base) {
  if (base == 0) return 1;
  long long int temp = power(val, base / 2);
  if (base & 1)
    return temp * temp * val;
  else
    return temp * temp;
}
int main() {
  long long int w, k, m;
  cin >> w >> m >> k;
  long long int rem = w;
  long long int low = m;
  long long int ans = 0;
  while (rem) {
    int cnt = cntdig(low);
    long long int val = power(10, cnt);
    long long int dif = val - low;
    if (dif * cnt <= rem / k) {
      rem -= dif * cnt * k;
      ans += dif;
      low = val;
    } else {
      ans += rem / (cnt * k);
      rem = 0;
    }
  }
  cout << ans << endl;
  return 0;
}
