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>
#pragma GCC optimize("O3")
using namespace std;
long long w, m, k;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
  cin >> w >> m >> k;
  long long aa = 0;
  int nc = 0;
  while (aa < m) aa = aa * 10 + 9, ++nc;
  long long m2 = m;
  while (w) {
    if ((aa - m + 1) <= w / k / nc) {
      w = w - k * (aa - m + 1) * nc;
      ++nc;
      m = aa + 1;
      aa = aa * 10 + 9;
    } else {
      m = m + w / k / nc;
      break;
    }
  }
  cout << m - m2;
  return 0;
}
