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())
po = m
no = 0
while po:
    po = po/10
    no = no + 1
ans = 0
di =0
while True:
    fans = pow(10,no) - m
    di = w
    w -= (fans*no*k)
    if w<0:
        break
    ans += (pow(10,no)-m)
    m = pow(10,no)
    no += 1
ji = di/no
ji = ji/k
ans += ji
print ans
    