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 main() {
  int test;
  unsigned long long int cost, n, k;
  cin >> cost >> n >> k;
  unsigned long long int p = 1;
  unsigned long long int cnt = 0, ans = 0;
  unsigned long long int base = 1, last = 9;
  unsigned long long int temp = n;
  while (temp > 0) {
    cnt++;
    temp /= 10;
    if (temp > 0) {
      base *= 10;
      last = (last * 10 + 9);
    }
  }
  unsigned long long int range = last - n + 1;
  unsigned long long int y = cnt * k;
  while (cost >= range * y) {
    cost -= range * y;
    ans += (range);
    cnt += 1;
    last = (last * 10 + 9);
    base = base * 10;
    n = base;
    range = last - n + 1;
    y = cnt * k;
  }
  unsigned long long int rem = cost / y;
  ans += (rem);
  cout << ans << endl;
}
