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=list(map(int,input().split()))
z=a=10**len(str(m))-m
if a*len(str(m))*k>=w:
    print(w//(len(str(m))*k))
else:
    w-=a*len(str(m))*k
    c=len(str(m))+1
    while w>0:
        a=9*10**(c-1)
        if a*c*k>=w:
            print(w//(c*k)+z)
            break
        w-=a*c*k
        z+=a
        c+=1