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;
long long base[18];
long long lim, cost, st;
void predo() {
  base[0] = 1;
  for (int i = 1; i < 18; i++) base[i] = base[i - 1] * 10;
}
int main() {
  cin >> lim >> st >> cost;
  lim /= cost;
  predo();
  int len = 0;
  long long f = st;
  while (f) {
    ++len;
    f /= 10;
  }
  long long ans = 0;
  while (lim && len * (base[len] - st) <= lim) {
    ans += base[len] - st;
    lim -= len * (base[len] - st);
    st = base[len];
    ++len;
  }
  ans += lim / len;
  cout << ans << endl;
  return 0;
}
