# -*- coding:utf-8 -*-
class Solution:
    def jumpFloor(self, number):
        # write code here
        if number <= 2: return number
        n1 = 1; n2 = 2; n3 = 0
        for i in range(3, number + 1):
            n3 = n1 + n2
            n1 = n2
            n2 = n3
        return n3