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

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.o: E = None
        self.q: D = None
        self.v: E = None
        self.s: A = None
        self.r: B = None
        self.txt = txt

e = A("e")
g = B("g")
l = C("l")
j = D("j")
k = E("k")
i = F("i")

e.u = g
e.r = l
e.p = k
e.t = i
e.w = i
g.p = i
g.t = i
g.s = e
l.p = i
l.z = j
l.t = g
l.o = k
j.v = l
j.u = l
j.r = e
k.z = e
i.o = k
i.v = k
i.q = j
i.s = e
i.r = g
assert l.o.z.t.v.z.txt == "
class A:
    def __init__(self, txt: str):
        self.u: B = None
        self.r: C = None
        self.p: E = None
        self.t: F = None
        self.w: F = None
        self.txt = txt

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.o: E = None
        self.q: D = None
        self.v: E = None
        self.s: A = None
        self.r: B = None
        self.txt = txt

e = A("e")
g = B("g")
l = C("l")
j = D("j")
k = E("k")
i = F("i")

e.u = g
e.r = l
e.p = k
e.t = i
e.w = i
g.p = i
g.t = i
g.s = e
l.p = i
l.z = j
l.t = g
l.o = k
j.v = l
j.u = l
j.r = e
k.z = e
i.o = k
i.v = k
i.q = j
i.s = e
i.r = g
assert l.o.z.t.v.z.txt == "e"