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 = raw_input().split()
W, M, K = int(W), int(M), int(K)

m = M

def max_number(n):
    res = 0
    for _ in range(n):
        res = res * 10 + 9
    return res


S = len(str(M))

if S * K <= W:
    while True:
        if (max_number(S) - M + 1) * K * S > W:
            M += W / (S * K) - 1
            break

        W -= (max_number(S) - M + 1) * K * S
        M = max_number(S)

        if (S + 1) * K <= W:
            M += 1
            S += 1
        else:
            break
else:
    M = m - 1

print M - m + 1
