def shangtaiji(n):
if n == 1:
return 1
if n == 2:
return 2
return shangtaijie(n-1) + shangtaijie(n-2)
def shangtaiji(n):
if n == 1:
return 1
if n == 2:
return 2
return shangtaijie(n-1) + shangtaijie(n-2)