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 cnt[10];
int calLen(long long n) {
  int ret = 0;
  while (n) {
    n /= 10;
    ret++;
  }
  return ret;
}
long long pow10(int len) {
  long long ret = 1;
  for (int i = 0; i < len; i++) ret *= 10;
  return ret;
}
int main() {
  long long w, m, k, ans = 0;
  cin >> w >> m >> k;
  int len = calLen(m);
  long long cnt = w / (k * len);
  while (cnt > 0) {
    long long next = m + cnt;
    long long lenNext = calLen(next);
    if (lenNext > len) cnt = pow10(len) - m, m = pow10(len);
    w = w - cnt * k * len;
    ans += cnt;
    if (lenNext > len) len = len + 1;
    cnt = w / (k * len);
  }
  cout << ans << endl;
}
