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 mod = 1000000007;
const int MAXN = 1000006;
long long suma(long long first) {
  long long bylo = 0, d = 1, p = 9;
  long long ret = 0;
  while (bylo < first) {
    long long tu = min(p, first - bylo);
    ret += tu * d;
    ++d;
    p *= 10;
    bylo += tu;
  }
  return ret;
}
long long w, m, k;
bool dasie(long long first) {
  long long r = suma(first + m - 1) - suma(m - 1);
  return r <= w / k;
}
int main() {
  scanf("%lld %lld %lld", &w, &m, &k);
  long long milion = 1000 * 1000;
  long long p = 0, kk = milion * milion * 1000 + 100;
  while (p + 1 < kk) {
    long long mid = (p + kk) / 2;
    if (dasie(mid))
      p = mid;
    else
      kk = mid;
  }
  printf("%lld\n", p);
  return 0;
}
