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
import sys
w,m,k=map(int,sys.stdin.readline().split())
w=int(w)
m=int(m)
k=int(k)
d=m
s=0
while(m>0):
          m=m/10
          s=s+1
m=d
d=s
k1=1
for x in range(0, s):
    k1*=10
ans=0
sum=0
while True:
    j=k1-m
    sum=sum+(j*k*d)
    if sum<w:
             ans+=k1-m
             m=k1
             k1*=10
             d=d+1
    elif sum==w:
         ans=ans+k1-m
         break
    else:
        sum=sum-(j*k*d)
        w=w-sum
        ans=ans+(w/(k*d))
        break
print(ans)