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 f(x):
    digs = len(str(x))
    
    ndig = digs*(x - 10**(digs-1) + 1)
    for i in range(1, digs):
        ndig += i * 9*10**(i-1)
    return ndig

a, b, c = map(int, input().split(' '))
num = a // c

need = num + f(b-1)

lo = 0
hi = 10**18

while lo < hi:
    mid = (lo + hi + 1) // 2
    if f(mid) > need:
        hi = mid - 1
    else:
        lo = mid
print(lo-b+1)
