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 int w, m, k;
long long int ans;
int f(long long int x) {
  int res = 0;
  while (x) {
    x /= 10;
    res++;
  }
  return res;
}
int main() {
  cin >> w >> m >> k;
  w /= k;
  long long int nxt = 1, cnt = f(m);
  for (int i = 0; i < cnt; i++) nxt *= 10ll;
  while ((nxt - m) * cnt <= w) {
    w -= (nxt - m) * cnt;
    ans += nxt - m;
    cnt++;
    m = nxt;
    nxt *= 10;
  }
  cout << ans + w / cnt << endl;
}
