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 w, m, k, x = 1, c = 0, y;
int funt(long long n) {
  string s;
  stringstream ss;
  ss << n;
  ss >> s;
  return (int)s.size();
}
int main() {
  cin >> w >> m >> k;
  y = w;
  int b;
  int len = funt(m);
  for (int i = 0; i < len; i++) x *= 10;
  while (y >= 0) {
    long long a = (x - m) * len * k;
    if (a < 0) a *= -1;
    if (a <= y)
      c += (x - m), y -= a, m = x;
    else {
      c += (y / (len * k)), y %= (len * k);
      break;
    }
    x *= 10, len++;
  }
  cout << c;
  return 0;
}
