A sequence S
n is defined as:
Where a, b, n, m are positive integers.┌x┐is the ceil of x. For example, ┌3.14┐=4. You are to calculate S
n.
You, a top coder, say: So easy!
There are several test cases, each test case in one line contains four positive integers: a, b, n, m. Where 0< a, m < 2
15, (a-1)
2< b < a
2, 0 < b, n < 2
31.The input will finish with the end of file.
For each the case, output an integer S
n.