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
(w, m, k) = map(int, raw_input().split())

sum_num = 0
st = m

for i in xrange(1, 100):
    end = (10 ** i) - 1
    if st > end:
        continue

    max_cnt = end - st + 1
    max_cost = max_cnt * k * i

    if max_cost <= w:
        sum_num += max_cnt
        w -= max_cost
        st = 10 ** i
    else:
        sum_num += w / (i * k)
        break

print sum_num
