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>
int count(long long n) {
  int temp = 0;
  while (n > 0) {
    n /= 10;
    temp++;
  }
  return temp;
}
int main() {
  long long b[18], a[18];
  long long i, j;
  a[0] = 1;
  b[0] = 1;
  a[1] = 9;
  b[1] = 10;
  for (i = 2; i <= 18; i++) {
    b[i] = b[i - 1] * 10;
    a[i] = a[i - 1] * 10;
  }
  long long w, k, m;
  scanf("%I64d %I64d %I64d", &w, &m, &k);
  w /= k;
  long long S = count(m);
  a[S] = a[S] - (m - b[S - 1]);
  long long track = 0;
  while (a[S] * S <= w) {
    w = w - a[S] * S;
    track += a[S];
    S++;
  }
  printf("%I64d", track + w / S);
}
