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 int W, M, K, result;
long long int f(long long int a) {
  long long int i, res = 1;
  for (i = 1; i <= a; i++) res *= 10;
  return res;
}
int main() {
  long long int i, j, a, t, mn;
  cin >> W >> M >> K;
  while (1) {
    j = 0;
    for (i = M; i; i /= 10) j++;
    a = f(j);
    a -= M;
    t = W / (j * K);
    mn = a < t ? a : t;
    if (!mn) break;
    result += mn;
    W -= mn * j * K;
    M = f(j);
  }
  cout << result;
  return 0;
}
