class A:
    def __init__(self, txt: str):
        self.u: E = None
        self.x: D = None
        self.p: F = None
        self.z: C = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.x: A = None
        self.u: F = None
        self.r: F = None
        self.s: D = None
        self.o: F = None
        self.t: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.q: E = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.x: A = None
        self.t: B = None
        self.q: A = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.x: A = None
        self.u: F = None
        self.r: F = None
        self.s: D = None
        self.o: F = None
        self.t: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.q: E = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.x: A = None
        self.t: B = None
        self.q: A = None
        self.txt = txt

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

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

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