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 int INF = 0x6fffffff;
const int inf = 522133279;
const long long llinf = 1e30;
const double eps = 1e-10;
const int MOD = 20121014;
long long doit(long long m) {
  long long cnt = 0;
  while (m) m /= 10, cnt++;
  return cnt;
}
int main() {
  long long w, m, k;
  cin >> w >> m >> k;
  w /= k;
  long long st = doit(m);
  long long s = (long long)pow(10.0, st);
  long long fin = 0;
  while (w > 0) {
    long long res = s - m;
    if (w < st * res) {
      fin += w / st;
      break;
    } else {
      w -= st * res;
      fin += res;
    }
    st++;
    m = s;
    s *= 10;
  }
  cout << fin << endl;
  return 0;
}
