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
read = lambda: tuple(map(int, input().split()))
w, m, k = read()
l = [10**v-1 for v in range(64)]
cv = m
s = lambda v: len(str(v))*k
cd = 0
ln = 0
for lv in l:
    if cv <= lv:
        d = min(w, (lv - cv + 1) * s(cv)) // s(cv)
        w -= d * s(cv)
        ln += d
        cv = lv + 1
        
    if w <= 0: break
        
        
        
print(ln)
