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 main() {
  long long lim, x;
  int i;
  cin >> lim >> x >> i;
  lim /= i;
  int d = 0;
  long long y = x;
  while (y > 0) {
    y /= 10;
    ++d;
  }
  y = x;
  long long up = 1;
  for (i = 0; i < d; i++) up *= 10;
  --up;
  --x;
  for (;;) {
    if (lim / d <= up - x) {
      x += lim / d;
      break;
    } else {
      lim -= (up - x) * d;
      x = up;
      ++d;
      up = up * 10 + 9;
    }
  }
  cout << x - y + 1 << endl;
}
