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 ws(long long x) {
  int ans = 0;
  while (x) ans++, x /= 10;
  return ans;
}
long long mypow(long long x, long long p) {
  long long ans = 1;
  while (p--) ans *= x;
  return ans;
}
int main() {
  long long w, m, k, ans = 0;
  while (cin >> w >> m >> k) {
    ans = 0;
    long long maxs = w / k, begx = ws(m);
    while (maxs > 0) {
      begx = ws(m);
      long long num = mypow(10, begx) - m;
      if (maxs - begx * num >= 0) {
        ans += num;
        maxs -= num * begx;
        m = mypow(10, begx);
      } else {
        ans += maxs / begx;
        maxs = 0;
        m = mypow(10, begx);
      }
    }
    cout << ans << endl;
  }
  return 0;
}
