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 string file = "file";
const string infile = file + ".in";
const string outfile = file + ".out";
const int INF = 0x3f3f3f3f;
long long S(long long n) {
  if (n == 0) return 1;
  long long result = 0;
  while (n != 0) {
    n /= 10;
    result++;
  }
  return result;
}
int main() {
  ostream &fout = cout;
  istream &fin = cin;
  long long W;
  long long M;
  long long K;
  fin >> W >> M >> K;
  long long Sol = 0;
  while (W) {
    long long length = S(M);
    long long nextNr = 1;
    for (int i = 0; i < length; i++) nextNr *= 10;
    long long left = nextNr - M;
    if (left <= W / (K * length)) {
      Sol += left;
      W -= left * length * K;
      M += left;
    } else {
      left = W / (K * length);
      Sol += left;
      W = 0;
    }
  }
  fout << Sol << "\n";
}
