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 numsz(long long x) {
  int i;
  for (i = 0; x > 0; x /= 10, i++)
    ;
  return i;
}
long long po(long long x) {
  long long ret = 1;
  while (x--) ret *= 10;
  return ret;
}
int main() {
  long long w, m, k;
  cin >> w >> m >> k;
  int N = numsz(m);
  long long rem1 = po(N) - m;
  long long P = pow(10, N);
  long long ret = 0;
  while (1) {
    long long x = min(rem1, w / (N * k));
    if (x == 0) break;
    ret += x;
    w -= x * N * k;
    rem1 = 9 * P;
    P *= 10;
    N++;
  }
  cout << ret << endl;
}
