class Solution(object):

    def climbStairs(self, n):
        """
        :type n: int
        :rtype: int
        """
        f = 0
        s = 1
        i = 0
        while i < n:
            f, s = s, f + s
            i = i + 1
        return s

1039eb1f7cfd0d28b054dca4ba73d8137b9c475d
<mask token>

class Solution(object):
    <mask token>

class Solution(object):

    def climbStairs(self, n):
        """
        :type n: int
        :rtype: int
        """
        f = 0
        s = 1
        i = 0
        while i < n:
            f, s = s, f + s
            i = i + 1
        return s
