# -*- coding:utf-8 -*-
class Solution:
    def jumpFloor(self, number):
        # write code here
        if number<=2: return number
        F_pre = 1
        F_cur = 2
        cnt = 2
        while cnt<number:
            F = F_cur + F_pre
            cnt = cnt + 1
            F_pre = F_cur
            F_cur = F
        return F