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 n, m, k;
  cin >> n >> m >> k;
  n /= k;
  vector<long long> S(20);
  long long base = 1;
  for (long long i = 0; i < 17; i++) {
    S[i] = 9LL * (i + 1) * base;
    base *= 10;
  }
  base = 10;
  for (long long i = 0; i < 17; i++) {
    if (m >= base) {
      n += S[i];
    } else {
      n += (m - base / 10) * (i + 1);
      break;
    }
    base *= 10;
  }
  long long seq = 9, ans = 0;
  for (long long i = 0; i < 17; i++) {
    if (n >= S[i]) {
      n -= S[i];
      ans += seq;
    } else {
      ans += n / (i + 1);
      break;
    }
    seq *= 10;
  }
  cout << ans - m + 1 << endl;
  return 0;
}
