class A:
    def __init__(self, txt: str):
        self.u: D = None
        self.p: A = None
        self.r: B = None
        self.y: A = None
        self.txt = txt

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

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

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

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

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

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

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

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

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

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

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

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