text: class Solution:
      def climbStairs(self, n: int) -> int:
          if n == 1:
              return 1
          dp = [0 for _ in range(n + 1)]
          dp[1] = 1
          dp[2] = 2
  
          for i in range(3, n+1):
              dp[i] = dp[i-1] + dp[i-2]
          return dp[n]
  