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 ans, w, k, m, n, i, j, p, s;
int main() {
  scanf(
      "%I64d"
      "%I64d"
      "%I64d"
      "\n",
      &w, &m, &k);
  p = 1;
  s = m;
  while (s) s /= 10, ++j, p *= 10;
  k = w / k;
  if ((p - m) * j > k)
    ans = k / j;
  else {
    ans = p - m;
    k = k - (p - m) * j;
    p = 9 * p;
    j++;
    while (p * j <= k) {
      k = k - p * j;
      ans += p;
      p *= 10;
      j++;
    }
    ans += (k / j);
  }
  printf(
      "%I64d"
      "\n",
      ans);
  return 0;
}
