迭代实现
temp = int(input('n = '))
num = [1, 1]
i = 2
while(i < temp):
num.append(num[i-1]+num[i-2])
i += 1
print('fab(n) =',num[temp-1])
temp = int(input('n = '))
num = [1, 1]
i = 2
while(i < temp):
num.append(num[i-1]+num[i-2])
i += 1
print('fab(n) =',num[temp-1])