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

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

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

class D:
    def __init__(self, txt: str):
        self.x: E = None
        self.q: C = None
        self.txt = txt

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

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

i = A("i")
h = B("h")
m = C("m")
e = D("e")
d = E("d")
f = F("f")
l = B("l")
g = F("g")
j = C("j")

i.v = l
i.o = l
i.q = g
i.u = e
h.o = d
h.q = d
h.z = l
h.s = e
m.r = d
m.p = d
m.u = e
m.y = j
e.x = d
e.q = m
d.w = l
f.z = e
f.r = i
f.o = i
f.u = l
f.s = l
f.q = h
l.o = d
l.q = d
l.z = h
l.s = e
g.z = e
g.r = i
g.o = i
g.u = l
g.q = l
g.s = h
j.r = d
j.p = d
j.u = e
j.y = m
assert f.u.z.o.w.s.q.u.txt == "
class A:
    def __init__(self, txt: str):
        self.v: B = None
        self.q: F = None
        self.o: B = None
        self.u: D = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.x: E = None
        self.q: C = None
        self.txt = txt

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

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

i = A("i")
h = B("h")
m = C("m")
e = D("e")
d = E("d")
f = F("f")
l = B("l")
g = F("g")
j = C("j")

i.v = l
i.o = l
i.q = g
i.u = e
h.o = d
h.q = d
h.z = l
h.s = e
m.r = d
m.p = d
m.u = e
m.y = j
e.x = d
e.q = m
d.w = l
f.z = e
f.r = i
f.o = i
f.u = l
f.s = l
f.q = h
l.o = d
l.q = d
l.z = h
l.s = e
g.z = e
g.r = i
g.o = i
g.u = l
g.q = l
g.s = h
j.r = d
j.p = d
j.u = e
j.y = m
assert f.u.z.o.w.s.q.u.txt == "e"