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 power(long long a, int b) {
  long long res = 1;
  for (int i = 0; i < b; ++i) {
    res *= a;
  }
  return res;
}
int nbc(long long a) {
  int b = 0;
  while (a > 0) {
    a /= 10;
    b++;
  }
  return b;
}
int main() {
  long long w, m, k, n, r, u, v, z, res = 0;
  cin >> w >> m >> k;
  n = w / k;
  z = nbc(m);
  r = pow(10, z) - m;
  if (n > r * z)
    res += r;
  else {
    res += n / z;
    cout << res << endl;
    return 0;
  }
  int i = z + 1;
  n -= r * z;
  while (n / i > 0) {
    if ((n / i) > pow(10, i)) {
      v = power(10, i) - power(10, i - 1);
    } else {
      v = n / i;
    }
    res += v;
    n -= v * i;
    ++i;
  }
  cout << res << endl;
  return 0;
}
