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
p=input().split()
w=int(p[0])
m=int(p[1])
a=m
cost=int(p[2])
c=0
while(m!=0):
    m=m//10
    c=c+1
sum=0
x=10**c-a
if cost*c*x>=w:
    print(w//(cost*c))
else:
    sum=sum+x
    w=w-cost*c*x
    for i in range(c+1,18):
        y=9*(10**(i-1))
        if(y*i*cost>=w):
            break
        else:
            w=w-cost*y*i
            sum=sum+y
    print(sum+w//(cost*i))
        
