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;
const long long INF = 100000000000000000LL;
long long ans;
long long he, dishu, cheng;
long long calcs(long long x) {
  if (x < 10) return x;
  long long ret = 0, i = 1, bit = 1;
  for (; i * 10 <= x; bit++, i *= 10) {
    ret += bit * 9 * i;
  }
  long long digit;
  digit = x / i % 10;
  ret += (digit - 1) * i * bit;
  ret += (x % i + 1) * bit;
  return ret;
}
int main() {
  cin >> he >> dishu >> cheng;
  for (long long left = 0, right = INF - dishu; left <= right;) {
    long long mid = (left + right) / 2;
    if (calcs(dishu + mid - 1) - calcs(dishu - 1) <= he / cheng)
      ans = mid, left = mid + 1;
    else
      right = mid - 1;
  }
  cout << ans << endl;
  return 0;
}
