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 fhelp(a):
    s = 1
    f = 10
    res = 0
    while a >= s:
        if (a >= s and a < f):
            break
        res += len(str(s)) * k * (f - s)
        s *= 10
        f *= 10  
    res += len(str(a)) * k * (a - s + 1)
    return res

def f(a, b):
    return fhelp(b) - fhelp(a - 1)
    
w, m, k = map(int, input().split())
#print(fhelp(10))
l = m - 1
r = 1000000000000000000
while (r - l > 1):
    c = (r + l) // 2
    if w >= f(m, c):
        l = c
    else:
        r = c
print(l - m + 1)
    