gistfile1.txt

Rabbit jumps upstairs.

N - number of steps that rabbit can jump at one time
X - total steps in stairs


N >= 1
X <= 300 
N <= X

======
if x == 6 and n == 3

there will be 14 unique routes. 

what if x == 17 and n == 5 ? :)

1 + 1 + 1 + 1 + 1 + 1
2 + 1 + 1 + 1 + 1
1 + 2 + 1 + 1 + 1
1 + 1 + 2 + 1 +1
1 + 1 + 1 + 2 + 1
1 + 1 + 1 + 1 + 2
3 + 1 + 1 + 1
1 + 3 + 1 + 1
1 + 1 + 3 + 1
1 + 1 + 1 + 3
3 + 2 + 1
2 + 3 + 1
1 + 2 + 3
1 + 3 + 1
3 + 3