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 power10(int len) {
  long long res = 1;
  long long pow = 10;
  while (len > 0) {
    if (len & 1) res = res * pow;
    pow = pow * pow;
    len >>= 1;
  }
  return res;
}
int digits(long long m) {
  int c = 0;
  while (m > 0) {
    m = m / 10;
    c++;
  }
  return c;
}
int main() {
  long long w, m, k;
  cin >> w >> m >> k;
  w = w / k;
  int digs = digits(m);
  long long pow10 = power10(digs);
  long long counter = 0;
  long long temp = pow10 - m;
  while (temp * digs < w) {
    w -= temp * digs;
    counter += temp;
    digs++;
    temp = power10(digs) - power10(digs - 1);
  }
  counter += w / digs;
  cout << counter << endl;
  return 0;
}
