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 dig(long long x) {
  long long k = 0;
  while (x > 0) x /= 10, k++;
  return k;
}
int32_t main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  long long t, i, j, n, w, m, k, l, r, ans = 0;
  cin >> w >> m >> k;
  for (i = 1; w > 0; i *= 10) {
    if (i < m) continue;
    n = dig(m);
    r = min((i - m), (w / (k * n)));
    w -= (r * n * k);
    ans += r;
    m = i;
    if (w < n * k) break;
  }
  cout << ans << "\n";
  return 0;
}
