Question
Bacterias
There are A Bacterias.
Each time Jerry shouts, the bacterias multiply by K times.
In order to have B or more slimes, at least how many times does Jerry need to shout?
Each time Jerry shouts, the bacterias multiply by K times.
In order to have B or more slimes, at least how many times does Jerry need to shout?
Input
Input is given from Standard Input in the following format:
A B K
Constraints
1≤A≤B≤10^9
2≤K≤10^9
All values in input are integers.
A B K
Constraints
1≤A≤B≤10^9
2≤K≤10^9
All values in input are integers.
Output
Print the answer.
Example
Sample Input 1
1 4 2
Sample Output 1
2
Sample Input 2
7 7 10
Sample Output 2
0
Sample Input 3
31 415926 5
Sample Output 3
6
(In first case, after the first shout Jerry will have 2 bacteria and after the second shout, he will have 4(2*2) bacteria.
1 4 2
Sample Output 1
2
Sample Input 2
7 7 10
Sample Output 2
0
Sample Input 3
31 415926 5
Sample Output 3
6
(In first case, after the first shout Jerry will have 2 bacteria and after the second shout, he will have 4(2*2) bacteria.