print ('hello world')

def fibonnaci():
    j = 1
    k = 1
    for i in range(0, 20):
        print(j)
        l = j
        j = j + k
        k = l

def powerof():
    for i in range(0, 20):
        print(i**2)

def poweroftwo():
    j = 2
    for i in range(0, 20):
        print(j)
        j = j*2

choice = int(input('Enter your choice: '))

if int(choice) == 1:
    fibonnaci()

if int(choice) == 2:
    powerof()

if int(choice) == 3:
    poweroftwo()