Python Checkboxes with tkinter and If Condition

Question

I would like to create some kind of prio generator. This is kept very simple. I have 8 different questions and depending on the answer a prioritization is output. This works so far also quite well. However, I have the error that my "Else" condition does not seem to work. Example: If question 1 and question 8 are selected, then the Else condition should output "not possible". Unfortunately this does not work. I have defined the possibilities and everything that is outside the defined rules should run into the else condition. Here is the code:

from tkinter import *

ws = Tk()
ws.title('Prio Guide')
ws.geometry('600x680')
ws.configure(bg="white")

text = StringVar()
label = Label(ws,
              text='empty',
              textvariable=text,
              bg="green")
prio1 = StringVar()
prio1_text = Label(ws, text='empty', textvariable=prio1, bg="white")
prio1.set("Prio 1 - Description")

prio2 = StringVar()
prio2_text = Label(ws, text='empty', textvariable=prio2, bg="white")
prio2.set("Prio 2- Description")

prio3 = StringVar()
prio3_text = Label(ws, text='empty', textvariable=prio3, bg="white")
prio3.set("Prio 3- Description")

prio4 = StringVar()
prio4_text = Label(ws, text='empty', textvariable=prio4, bg="white")
prio4.set("Prio 4- Description")


# define the Prio
def prio():
    if cb.get() == 1 or cb1.get() == 1 or cb2.get() == 1 or cb.get() & cb1.get() == 1 or cb2.get() & cb1.get() == 1 or cb.get() & cb1.get() & cb2.get() == 1:
        text.set("Prio 1")

    elif cb3.get() == 1 or cb4.get() == 1 or cb3.get() & cb4.get() == 1:
        text.set("Prio 2")

    elif cb5.get() == 1 or cb5.get() & cb6.get() == 1:
        text.set("Prio 3")
    elif cb7.get() == 1 or cb6.get() & cb7.get() == 1:
        text.set("Prio 4")
    else:
        text.set("not possible")


# create IntVar fot the value of checkboxes
cb = IntVar()
cb1 = IntVar()
cb2 = IntVar()
cb3 = IntVar()
cb4 = IntVar()
cb5 = IntVar()
cb6 = IntVar()
cb7 = IntVar()
# create checkbutton
Checkbutton(ws,
            bg="white",
            text="q1",
            variable=cb,
            onvalue=1,
            offvalue=0,
            command=prio, ).pack(anchor=W, padx=(100, 10))
Checkbutton(ws,
            bg="white",
            text="q2",
            variable=cb1,
            onvalue=1,
            offvalue=0,
            command=prio).pack(anchor=W, padx=(100, 10))
Checkbutton(ws,
            bg="white",
            text="q3",
            variable=cb2,
            onvalue=1,
            offvalue=0,
            command=prio).pack(anchor=W, padx=(100, 10))
Checkbutton(ws,
            bg="white",
            text="q4",
            variable=cb3,
            onvalue=1,
            offvalue=0,
            command=prio).pack(anchor=W, padx=(100, 10))
Checkbutton(ws,
            bg="white",
            text="q5",
            variable=cb4,
            onvalue=1,
            offvalue=0,
            command=prio).pack(anchor=W, padx=(100, 10))
Checkbutton(ws,
            bg="white",
            text="q6",
            variable=cb5,
            onvalue=1,
            offvalue=0,
            command=prio).pack(anchor=W, padx=(100, 10))
Checkbutton(ws,
            bg="white",
            text="q7",
            variable=cb6,
            onvalue=1,
            offvalue=0,
            command=prio).pack(anchor=W, padx=(100, 10))
Checkbutton(ws,
            bg="white",
            text="q8",
            variable=cb7,
            onvalue=1,
            offvalue=0,
            command=prio).pack(anchor=W, padx=(100, 10))

label.pack(anchor=S)
prio1_text.pack(anchor=S, padx=(100, 10))
prio2_text.pack(anchor=S, padx=(100, 10))
prio3_text.pack(anchor=S, padx=(100, 10))
prio4_text.pack(anchor=S, padx=(100, 10))
ws.mainloop()

Thanks for your help!