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 main() {
  long long w, m, k, i, j, p, q, r, s, t, x, y, z, flag, flg,
      mxval = 99999999999999999, ans, cnt, ttl, bs = 1;
  map<long long, long long> mp;
  scanf("%lld %lld %lld", &w, &m, &k);
  long long lo, hi, mid;
  for (i = 1; i <= 17; i++) {
    p = (bs * 10) - 1;
    bs = p + 1;
    mp[i] = p;
  }
  mp[0] = 0;
  lo = m;
  hi = mxval;
  while (hi - lo >= 7) {
    mid = (lo + hi) / 2;
    x = m;
    y = mid;
    cnt = 0;
    ttl = 0;
    flag = 1;
    for (i = 1; i <= 17; i++) {
      if (x > mp[i - 1] && x <= mp[i]) {
        if (y <= mp[i]) {
          r = max(x, mp[i - 1] + 1);
          s = y - r + 1;
          cnt = (i * k) * s;
          ttl = ttl + cnt;
          break;
        } else {
          r = max(x, mp[i - 1] + 1);
          s = mp[i] - r + 1;
          cnt = (i * k) * s;
          ttl = ttl + cnt;
          x = mp[i] + 1;
          if (x > y) break;
        }
      }
    }
    if (ttl >= 1 && ttl <= w)
      lo = mid;
    else
      hi = mid - 1;
  }
  flg = 0;
  for (j = hi; j >= lo; j--) {
    x = m;
    y = j;
    cnt = 0;
    ttl = 0;
    flag = 1;
    for (i = 1; i <= 17; i++) {
      if (x > mp[i - 1] && x <= mp[i]) {
        if (y <= mp[i]) {
          r = max(x, mp[i - 1] + 1);
          s = y - r + 1;
          cnt = (i * k) * s;
          ttl = ttl + cnt;
          break;
        } else {
          r = max(x, mp[i - 1] + 1);
          s = mp[i] - r + 1;
          cnt = (i * k) * s;
          ttl = ttl + cnt;
          x = mp[i] + 1;
          if (x > y) break;
        }
      }
    }
    if (ttl >= 1 && ttl <= w) {
      flg = 1;
      ans = j;
      break;
    }
  }
  if (flg == 1)
    printf("%lld\n", ans - m + 1);
  else
    printf("0\n");
  return 0;
}
