def func(a, b, listC):
    '''
    Go away.
    '''
    x = 17
    a = a + x
    b = b - x
    c[0] = x
    c[1] = a
    c[2] = b
    print(f"In func(), the value of a is {a}")
    print(f"In func(), the value of b is {b}")
    print(f"In func(), the value of c is {listC}")

a = 10
b = 20
c = [0, 0, 0]
func(b, a, c)
print(f"In main, the value of a is {a}")
print(f"In main, the value of b is {b}")
print(f"In main, the value of b is {c}")