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
a = map(int, raw_input().split())
m = a[0]
n = a[1]
k = a[2]
i=n;
len=0;
while(i>0):
    len=len+1;
    i/=10;
n=n-1;
j=1;
i=1;
while(i<=len):
    j=j*10;
    i=i+1;
j=j-1;
ans=0;
cost=k*len;
while(m>0):
    if(j-n<m/cost):
        ans=ans+j-n;
    else:
        ans=ans+m/cost;
    m=m-(j-n)*cost;
    n=j;
    j=((j+1)*10)-1;
    cost=cost+k;
print(ans);
    
