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())
cur = len(str(m))
g = 9
base = 1
g = g*(10**(cur-1))
base = base*(10**(cur-1))
gg = g - (m - base)
ans = 0
while(w):
	if(w>cur*gg*k):
		w-=cur*gg*k
		ans +=gg
		cur+=1
		gg = g*10
		g*=10
	else:
		ans += w//(cur*k)
		break
print(ans)