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,input().split())
def erc(x) :
    an = 0
    for i in range(x) :
        an = an * 10 + 9
    return an
def s(x) :
    y = 0
    while x > 0 :
        y += 1
        x //= 10
    return y
cnt = 0
for i in range(s(m),30) :
    cnt += min(erc(i) - m + 1,w // (i * k))
    #print(erc(i))
    if(erc(i) - m + 1 >= w / (i * k)) :
        #print(min(erc(i) - m + 1 , w // (i * k)))
        #print(w , i)
        w -= (min(erc(i) - m + 1 , w // (i * k)) * k * i)
        #print(w)
        break
    #print(min(erc(i) - m + 1,w // (i * k)))
    w -= min(erc(i) - m + 1 , w // (i * k)) * k * i
    m = 1
    for j in range(i) :
        m = m * 10
    #print(m)
print(int(cnt))