class A:
    def __init__(self, txt: str):
        self.z: C = None
        self.q: B = None
        self.x: C = None
        self.o: B = None
        self.s: C = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.z: D = None
        self.p: D = None
        self.v: D = None
        self.o: C = None
        self.u: E = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.u: C = None
        self.y: B = None
        self.q: B = None
        self.o: B = None
        self.s: A = None
        self.txt = txt

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

e = A("e")
b = B("b")
f = C("f")
n = D("n")
j = E("j")
a = E("a")
i = A("i")
l = C("l")
c = C("c")

e.z = f
e.q = b
e.o = b
e.x = c
e.s = l
b.z = n
b.p = n
b.v = n
b.o = c
b.u = j
f.t = n
f.o = l
n.u = f
n.y = b
n.q = b
n.o = b
n.s = e
j.u = a
j.r = c
a.u = j
a.r = l
i.z = c
i.q = b
i.o = b
i.x = f
i.s = f
l.t = n
l.o = c
c.t = n
c.o = f
assert n.y.z.s.o.u.u.r.t.s.txt == "
class A:
    def __init__(self, txt: str):
        self.z: C = None
        self.q: B = None
        self.x: C = None
        self.o: B = None
        self.s: C = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.z: D = None
        self.p: D = None
        self.v: D = None
        self.o: C = None
        self.u: E = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.u: C = None
        self.y: B = None
        self.q: B = None
        self.o: B = None
        self.s: A = None
        self.txt = txt

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

e = A("e")
b = B("b")
f = C("f")
n = D("n")
j = E("j")
a = E("a")
i = A("i")
l = C("l")
c = C("c")

e.z = f
e.q = b
e.o = b
e.x = c
e.s = l
b.z = n
b.p = n
b.v = n
b.o = c
b.u = j
f.t = n
f.o = l
n.u = f
n.y = b
n.q = b
n.o = b
n.s = e
j.u = a
j.r = c
a.u = j
a.r = l
i.z = c
i.q = b
i.o = b
i.x = f
i.s = f
l.t = n
l.o = c
c.t = n
c.o = f
assert n.y.z.s.o.u.u.r.t.s.txt == "e"