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

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

class C:
    def __init__(self, txt: str):
        self.x: F = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.x: E = None
        self.w: B = None
        self.p: A = None
        self.u: E = None
        self.txt = txt

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

e = A("e")
j = B("j")
b = C("b")
n = D("n")
k = E("k")
m = F("m")
h = E("h")
i = F("i")

e.s = h
e.r = n
j.w = b
j.z = b
j.v = k
b.x = m
n.o = k
k.x = h
k.u = h
k.w = j
k.p = e
m.q = b
m.t = i
m.p = j
m.o = j
h.x = k
h.u = k
h.w = j
h.p = e
i.q = b
i.t = m
i.p = j
i.o = j
assert i.o.v.w.z.x.t.o.z.txt == "
class A:
    def __init__(self, txt: str):
        self.s: E = None
        self.r: D = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.x: F = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.x: E = None
        self.w: B = None
        self.p: A = None
        self.u: E = None
        self.txt = txt

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

e = A("e")
j = B("j")
b = C("b")
n = D("n")
k = E("k")
m = F("m")
h = E("h")
i = F("i")

e.s = h
e.r = n
j.w = b
j.z = b
j.v = k
b.x = m
n.o = k
k.x = h
k.u = h
k.w = j
k.p = e
m.q = b
m.t = i
m.p = j
m.o = j
h.x = k
h.u = k
h.w = j
h.p = e
i.q = b
i.t = m
i.p = j
i.o = j
assert i.o.v.w.z.x.t.o.z.txt == "b"