暴力破解，卡死+2 from functools import cache @cache def triangle(n:int)->list[int]: res=[] if n==1: return [1] if n==2: return [1,1,1] prev=triangle(n-1) res.append(prev[0]) res.append(sum(prev[0:2])) for i in range(len(prev)-2): res.append(sum(prev[i:i+3])) res.append(sum(prev[-2:])) res.append(prev[-1]) return res while True: try: n=int(input()) for i,e in enumerate(triangle(n)): if e%2==0: print(i+1) break else: print(-1) except: break