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>
long long get(long long a) {
  long long ret = 0;
  long long now = 1;
  long long t = 1;
  for (;;) {
    if (now * 10 > a) {
      ret += (a - now + 1) * t;
      break;
    }
    ret += now * 9 * t;
    now *= 10;
    t++;
  }
  return ret;
}
int main() {
  long long gen, st, tim;
  scanf("%I64d%I64d%I64d", &gen, &st, &tim);
  gen /= tim;
  long long beg = st - 1, end = 20000000000000000LL;
  for (;;) {
    long long med = (beg + end) / 2 + 1;
    if (get(med) - get(st - 1) > gen) {
      end = med - 1;
    } else {
      beg = med;
    }
    if (beg == end) {
      printf("%I64d\n", beg - st + 1);
      break;
    }
  }
}
