¡¡¡¡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 < 215, (a-1)2< b < a2, 0 < b, n < 231.The input will finish with the end of file.
2 3 1 2013
2 3 2 2013
2 2 1 2013