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 dec_len(n):
    s=str(n)
    return len(s)

def last(mx,m,k):
    return mx-(mx-m)%k

def quanto(m,st):
    mx=int(10**st)
    cl=mx-m
    m=mx
    return cl,m
        

w,m,k=map(int,input().split(' '))

d=0

while 1:
    l=dec_len(m)
    cl,nm=quanto(m,l)
    #print('cl={} nm={} w={}'.format(cl,nm,w))
    if w>cl*k*l:
        w-=cl*k*l
        d+=cl
    else:
        cl=w//(k*l)
        d+=cl
        break
    m=nm
    
print(d)

