A stairway has 100 steps. You can climb it by one step at a time, or by two steps. How many different ways to ascend this stairway exist?
Do you have to end right on the last step? In that case it would be the number of numbers which you can evenly divide by 100.......1,2,4,5,10,20,25,50,100.........9 times.
The other way I see the question is that you do not have to end exactly on the last step, and the problem is really looking for the sum of the numbers from 1 to 100.......5050.