n = int(input("enter a number: "))
while True:
    if n == 0:
        print("ngao ngo a?!")
    elif n == 1:
        print("ngao ngo a?!")
    elif n == 2:
        print("day la so nguyen to nho nhat")
    elif n %2 == 0:
        print("day khong phai la so nguyen to")
    elif for i in range(i):
        n %i
