class Solution: def solve(self , nums: str) -> int: # write code here l = len(nums) dp = [1 for _ in range(l+1)] for i in range(1, l+1): if i == 1: if nums[i-1] == '0': dp[i] = 0 else: dp[i] = 1 else: if nums[i-1] == '0' and int(nums[i-2]) > 2: return 0 elif nums[i-1] == '0' or nums[i-2] == '0' or int(nums[i-2]+nums[i-1]) < 1 or int(nums[i-2]+nums[i-1]) > 26: dp[i] = dp[i-1] else: dp[i] = dp[i-2] + dp[i-1] return dp[-1]