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 long long mod = 1e9 + 7;
const long long N = 1e5 + 7;
vector<pair<long long, long long>> vx;
int32_t main() {
  long long w, n, k;
  cin >> w >> n >> k;
  long long start = 9;
  long long dig = 1;
  while (n > start) {
    start = start * 10 + 9;
    dig++;
  }
  vx.push_back({start - n + 1, dig});
  start++;
  while (start <= (1e17)) {
    dig++;
    vx.push_back({start * 9, dig});
    start *= 10;
  }
  long long ans = 0;
  for (auto i : vx) {
    long long num = min(i.first, w / (k * i.second));
    ans += num;
    w -= num * i.second * k;
    if (w <= 0) break;
  }
  cout << ans;
  return 0;
}
