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 main() {
  long long m;
  long long w;
  long long k;
  long long z;
  long long s;
  long long sz = 0;
  long long i = 0;
  long long n;
  long long ans = 0;
  cin >> w >> m >> k;
  s = m;
  z = w / k;
  while (s != 0) {
    sz++;
    s = s / 10;
  }
  n = pow(10, sz);
  while (1) {
    if (z > (n - m) * sz) {
      z = z - (n - m) * sz;
      ans = ans + n - m;
      m = n;
      sz = sz + 1;
      n = n * 10;
      continue;
    }
    if (z == (n - m) * sz) {
      ans = ans + n - m;
      break;
    }
    if (z < (n - m) * sz) {
      ans = ans + (z / sz);
      break;
    }
  }
  cout << ans << endl;
}
