class A:
    def __init__(self, txt: str):
        self.w: D = None
        self.v: C = None
        self.s: B = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.s: D = None
        self.q: F = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: A = None
        self.x: D = None
        self.y: B = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.y: E = None
        self.o: F = None
        self.v: A = None
        self.x: D = None
        self.q: D = None
        self.z: E = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.r: D = None
        self.z: D = None
        self.v: D = None
        self.t: F = None
        self.w: F = None
        self.q: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.v: A = None
        self.s: E = None
        self.o: A = None
        self.txt = txt

i = A("i")
k = B("k")
h = C("h")
j = D("j")
b = E("b")
c = F("c")
e = D("e")

i.w = e
i.v = h
i.s = k
k.s = j
k.q = c
h.t = i
h.x = j
h.y = k
j.y = b
j.z = b
j.o = c
j.v = i
j.x = e
j.q = e
b.r = e
b.z = j
b.v = j
b.t = c
b.w = c
b.q = h
c.v = i
c.o = i
c.s = b
e.y = b
e.z = b
e.o = c
e.v = i
e.x = j
e.q = j
assert h.t.w.x.o.v.txt == "
class A:
    def __init__(self, txt: str):
        self.w: D = None
        self.v: C = None
        self.s: B = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.s: D = None
        self.q: F = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: A = None
        self.x: D = None
        self.y: B = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.y: E = None
        self.o: F = None
        self.v: A = None
        self.x: D = None
        self.q: D = None
        self.z: E = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.r: D = None
        self.z: D = None
        self.v: D = None
        self.t: F = None
        self.w: F = None
        self.q: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.v: A = None
        self.s: E = None
        self.o: A = None
        self.txt = txt

i = A("i")
k = B("k")
h = C("h")
j = D("j")
b = E("b")
c = F("c")
e = D("e")

i.w = e
i.v = h
i.s = k
k.s = j
k.q = c
h.t = i
h.x = j
h.y = k
j.y = b
j.z = b
j.o = c
j.v = i
j.x = e
j.q = e
b.r = e
b.z = j
b.v = j
b.t = c
b.w = c
b.q = h
c.v = i
c.o = i
c.s = b
e.y = b
e.z = b
e.o = c
e.v = i
e.x = j
e.q = j
assert h.t.w.x.o.v.txt == "i"