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

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

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

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

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

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

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

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

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

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

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

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

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