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())
z=m
dig=0
while z>0:
	dig+=1;
	z=z//10
if(dig*k>w):
	print(0)
	exit(0)
lo=m-1
hi=w+m+5
while lo+1<hi:
	mid=(lo+hi)//2
	cost, t, d=0,0,0
	x=mid
	while x>0:
		x=x//10
		d+=1
	if(d==dig):
		cost=(mid-m+1)*d*k
	else:
		t=pow(10, dig)
		last=m
		c=dig
		while t<=mid:
			cost+=(t-last)*c*k
			c+=1
			last=t
			t=t*10
		t=t//10
		cost+=(mid-t+1)*c*k
	if(cost<=w):
		lo=mid
	else:
		hi=mid
print(lo-m+1)
