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 d(long long x) {
  int cnt = 0;
  while (x) {
    cnt++;
    x = x / 10;
  }
  return cnt;
}
long long pow(long long s) {
  long long sum = 1;
  while (s--) {
    sum *= 10;
  }
  return sum;
}
int main() {
  long long w, m, n;
  while (cin >> w >> m >> n) {
    long long cnt = 0;
    w = w / n;
    long long s = d(m);
    while (w > 0) {
      if (w > s * (pow(s) - m)) {
        w -= s * (pow(s) - m);
        cnt += pow(s) - m;
      } else {
        cnt += w / s;
        w = 0;
      }
      m = pow(s);
      s++;
    }
    cout << cnt << endl;
  }
  return 0;
}
