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 logg(long long x) {
  int ret = 0;
  while (x) {
    ret++;
    x /= 10;
  }
  return ret;
}
long long pw(int x) {
  long long ret = 1;
  while (x--) ret *= 10;
  return ret;
}
pair<long long, long long> to(long long x) {
  return make_pair(logg(x) * (pw(logg(x)) - x), (pw(logg(x)) - x));
}
int main() {
  long long w, m, k;
  scanf("%lld%lld%lld", &w, &m, &k);
  w /= k;
  long long ans = 0;
  while (1) {
    pair<long long, long long> tt;
    tt = to(m);
    long long t = tt.first;
    if (w > t) {
      ans += tt.second;
      w -= t;
      m = pw(logg(m));
    } else {
      ans += (w / (logg(m)));
      break;
    }
  }
  printf("%lld\n", ans);
  return 0;
}
