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 len(long long n) {
  int l = 0;
  if (!n) l++;
  while (n) {
    n /= 10;
    l++;
  }
  return l;
}
int main() {
  long long p, i, j, n, k, w, m, ans, a, ttl;
  while (cin >> w) {
    cin >> m >> k;
    ans = 0;
    n = len(m);
    p = 1;
    for (i = 1; i <= n; i++) p *= 10;
    j = p - m;
    ttl = 0;
    while (ans <= w) {
      i = n * k;
      a = (w - ans) / i;
      if (a >= j) {
        ans += n * k * j;
        if (ans <= w) ttl += (p - m);
        m = p;
        n++;
        p *= 10;
        j = p - m;
      } else {
        ans += n * k * a;
        if (ans <= w) ttl += a;
        break;
      }
    }
    cout << ttl << endl;
  }
  return 0;
}
