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;
const int MAXINT = 1 << 31 - 1;
const long long MAXLONG = (long long)1 << 63 - 1;
long long w, k;
long long len, num;
char m[20];
int main() {
  while (cin >> w >> m >> k) {
    len = strlen(m);
    num = w / k;
    long long rem = num;
    long long res = 0;
    long long s;
    sscanf(m, "%I64d", &s);
    long long t = pow(10.0, 1.0 * len);
    while (rem >= len) {
      if (rem >= (t - s) * len) {
        rem -= (t - s) * len;
        res += t - s;
      } else {
        long long once = rem / len;
        res += once;
        rem = 0;
      }
      len++;
      s = t;
      t *= 10;
    }
    cout << res << endl;
  }
  return 0;
}
