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

class B:
    def __init__(self, txt: str):
        self.u: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.q: D = None
        self.o: B = None
        self.r: A = None
        self.t: A = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.p: C = None
        self.q: D = None
        self.s: A = None
        self.v: C = None
        self.y: D = None
        self.t: F = None
        self.txt = txt

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

f = A("f")
h = B("h")
g = C("g")
j = D("j")
l = E("l")
i = F("i")
e = A("e")

f.x = l
f.t = g
h.u = l
g.q = j
g.o = h
g.r = e
g.t = e
j.x = l
j.v = l
j.y = f
j.q = g
l.p = g
l.v = g
l.q = j
l.y = j
l.s = f
l.t = i
i.p = h
i.u = h
i.t = h
i.v = f
i.s = f
i.r = j
e.x = l
e.t = g
assert l.t.u.u.t.s.x.txt == "
class A:
    def __init__(self, txt: str):
        self.x: E = None
        self.t: C = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.u: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.q: D = None
        self.o: B = None
        self.r: A = None
        self.t: A = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.p: C = None
        self.q: D = None
        self.s: A = None
        self.v: C = None
        self.y: D = None
        self.t: F = None
        self.txt = txt

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

f = A("f")
h = B("h")
g = C("g")
j = D("j")
l = E("l")
i = F("i")
e = A("e")

f.x = l
f.t = g
h.u = l
g.q = j
g.o = h
g.r = e
g.t = e
j.x = l
j.v = l
j.y = f
j.q = g
l.p = g
l.v = g
l.q = j
l.y = j
l.s = f
l.t = i
i.p = h
i.u = h
i.t = h
i.v = f
i.s = f
i.r = j
e.x = l
e.t = g
assert l.t.u.u.t.s.x.txt == "l"