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=map(int,raw_input().split())
t=m;
c=0;
while(t):
    c=c+1
    t=t//10;
p=10**c-m;
if(p*c*k==w):
    print(p)
elif(p*c*k>w):
    print(w//(c*k))
else:
    s=p;
    w=w-p*c*k;
    for i in range(c+1,18):
        x=9*(10**(i-1));
        q=x*(i*k)
        if(q<w):
            w=w-q;
            s=s+x;
        else:
            s=s+w//(i*k)
            print(s)
            exit(0)