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 int numdigits(long long int n) {
  long long int ans = 1;
  while (n / 10 != 0) {
    ans++;
    n = n / 10;
  }
  return ans;
}
long long int f(long long int a, long long int b, long long int s,
                long long int d) {
  long long int temp = (b - a) * d;
  if (temp < s) {
    return (temp / d + f(b, b * 10, s - temp, d + 1));
  } else {
    return s / d;
  }
}
long long int powr(long long int a, long long int b) {
  if (b == 0)
    return 1;
  else
    return a * powr(a, b - 1);
}
int main() {
  long long int w, k, m;
  cin >> w >> m >> k;
  long long int s = w / k;
  long long int d = numdigits(m);
  long long int ans = f(m, powr(10, d), s, d);
  cout << ans << endl;
  return 0;
}
