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 w, m, k, l;
long long upper(long long v) {
  long long s = 1;
  while (s <= v) {
    s *= 10;
  }
  return s;
}
long long S(long long v) {
  long long len = 0;
  while (v != 0) {
    v /= 10;
    ++len;
  }
  return len;
}
int main() {
  cin >> w >> m >> k;
  l = w / k;
  long long ml = 0;
  while (l > 0) {
    long long ub = upper(m);
    long long len = S(m);
    if ((ub - m) * len < l) {
      l -= (ub - m) * len;
      ml += (ub - m);
      m = ub;
    } else {
      ml += l / len;
      l = 0;
    }
  }
  cout << ml << endl;
}
