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

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

class C:
    def __init__(self, txt: str):
        self.q: E = None
        self.s: B = None
        self.o: E = None
        self.p: E = None
        self.txt = txt

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

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

e = A("e")
n = B("n")
m = C("m")
k = D("k")
c = E("c")
a = A("a")

e.u = m
e.s = m
e.o = k
e.z = k
n.r = e
n.u = c
n.p = k
n.s = m
m.q = c
m.o = c
m.p = c
m.s = n
k.o = e
c.o = a
c.u = a
c.s = e
c.t = m
a.u = m
a.s = m
a.o = k
a.z = k
assert e.s.o.t.txt == "
class A:
    def __init__(self, txt: str):
        self.u: C = None
        self.o: D = None
        self.s: C = None
        self.z: D = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.q: E = None
        self.s: B = None
        self.o: E = None
        self.p: E = None
        self.txt = txt

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

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

e = A("e")
n = B("n")
m = C("m")
k = D("k")
c = E("c")
a = A("a")

e.u = m
e.s = m
e.o = k
e.z = k
n.r = e
n.u = c
n.p = k
n.s = m
m.q = c
m.o = c
m.p = c
m.s = n
k.o = e
c.o = a
c.u = a
c.s = e
c.t = m
a.u = m
a.s = m
a.o = k
a.z = k
assert e.s.o.t.txt == "m"