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
s=raw_input().split()
w = long(s[0])
m=long(s[1])
k=long(s[2])

x=m
d=0
while x!=0:
        d+=1
        x/=10
c=0
diff = 10**d - m
ans=0
while c<=w:
        if w>= c+diff*d*k:
                ans+=diff
                c+=diff*d*k
        else:
                t=(w-c)/(d*k)
                ans+=t
                c+=t*d*k
                break
        d+=1
        diff = 10**d - 10**(d-1)

print ans
