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().strip().split())

n = len(str(m))

tmp = 10**n - m
if w < tmp*n*k:
    res = w/(n*k)
    w = 0
else:
    res = tmp
    w -= tmp*n*k

n+=1

while w - n*k*(10**(n)) >= 0:
    res += (10**(n)-10**(n-1))
    w -= n*k*(10**(n)-10**(n-1))
    n += 1
    # print res, w, n


res += (w)/(n*k)

print res


# w,m,k = map(int,sys.stdin.readline().strip().split())
# res = 0
# while w - len(str(m))*k >= 0:
#     w -=len(str(m))*k
#     res += 1
#     m += 1

# print res