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
def cnt(x, y):
  return y-x

w, m, k = map(int, input().split())
p, d, res = 1, 0, 0
while p <= m:
  p *= 10
  d += 1
while cnt(m, p)*d*k <= w:
  w -= cnt(m, p)*d*k
  res += cnt(m, p)
  m = p
  p *= 10
  d += 1
lo, hi = m, p
while hi-lo > 1:
  mid = (lo+hi)//2
  if (cnt(m, mid)*d*k <= w): lo = mid
  else: hi = mid
res += cnt(m, lo)

print(res)
