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 s(unsigned long long n) {
  int ret = 0;
  do {
    n /= 10;
    ret++;
  } while (n > 0);
  return ret;
}
unsigned long long max_dig(int cnt) {
  unsigned long long ret = 1;
  for (int i = 0; i < cnt; i++) {
    ret *= 10;
  }
  return ret - 1;
}
int main() {
  unsigned long long w, m, k;
  while (cin >> w >> m >> k) {
    w /= k;
    unsigned long long ret = 0;
    unsigned long long smax;
    int sv;
    while (w > 0) {
      sv = s(m);
      smax = max_dig(sv);
      if ((smax - m + 1) * sv > w) {
        ret += w / sv;
        w = 0;
      } else {
        ret += smax - m + 1;
        w -= (smax - m + 1) * sv;
        m = smax + 1;
      }
    }
    cout << ret << endl;
  }
  return 0;
}
