def fibona(x):
if x==1 or x==2:
f=1
for i in range(3,x+1):
f=fibona(x-1)+fibona(x-2)
return f
n=int(input("请输入数列第几项："))
m=fibona(n)
print("数列的第"+str(n)+"项的值为"+str(m))