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

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

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

class D:
    def __init__(self, txt: str):
        self.z: E = None
        self.txt = txt

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

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.z: E = None
        self.txt = txt

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

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

e.p = n
e.y = n
e.t = j
e.z = j
e.w = c
c.t = a
c.s = e
n.u = i
n.t = d
n.p = d
a.z = b
l.z = b
l.r = n
l.v = d
k.t = j
k.s = e
i.p = d
i.y = d
i.t = j
i.z = a
i.w = k
j.z = l
d.u = i
d.t = n
d.p = n
b.z = l
b.r = d
b.v = n
assert b.v.u.z.z.z.r.p.u.txt == "i"