class A:
    def __init__(self, txt: str):
        self.x: F = None
        self.v: E = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.r: F = None
        self.q: B = None
        self.o: E = None
        self.w: E = None
        self.y: A = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.z: A = None
        self.s: B = None
        self.x: E = None
        self.w: D = None
        self.q: C = None
        self.u: B = None
        self.txt = txt

j = A("j")
a = B("a")
b = C("b")
e = D("e")
g = E("g")
m = F("m")
l = C("l")
k = D("k")
h = E("h")
d = B("d")

j.x = m
j.v = h
a.v = e
a.z = j
a.o = h
a.y = k
a.p = l
b.r = m
b.q = d
b.o = g
b.w = h
b.y = j
e.p = k
e.u = k
e.r = g
e.v = h
e.s = d
g.r = j
g.t = j
m.z = j
m.s = d
m.x = h
m.w = e
m.q = b
m.u = a
l.r = m
l.q = a
l.o = g
l.w = h
l.y = j
k.p = e
k.u = e
k.r = g
k.v = g
k.s = a
h.r = j
h.t = j
d.v = k
d.z = j
d.o = h
d.y = e
d.p = b
assert b.r.w.r.r.x.txt == "
class A:
    def __init__(self, txt: str):
        self.x: F = None
        self.v: E = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.r: F = None
        self.q: B = None
        self.o: E = None
        self.w: E = None
        self.y: A = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.z: A = None
        self.s: B = None
        self.x: E = None
        self.w: D = None
        self.q: C = None
        self.u: B = None
        self.txt = txt

j = A("j")
a = B("a")
b = C("b")
e = D("e")
g = E("g")
m = F("m")
l = C("l")
k = D("k")
h = E("h")
d = B("d")

j.x = m
j.v = h
a.v = e
a.z = j
a.o = h
a.y = k
a.p = l
b.r = m
b.q = d
b.o = g
b.w = h
b.y = j
e.p = k
e.u = k
e.r = g
e.v = h
e.s = d
g.r = j
g.t = j
m.z = j
m.s = d
m.x = h
m.w = e
m.q = b
m.u = a
l.r = m
l.q = a
l.o = g
l.w = h
l.y = j
k.p = e
k.u = e
k.r = g
k.v = g
k.s = a
h.r = j
h.t = j
d.v = k
d.z = j
d.o = h
d.y = e
d.p = b
assert b.r.w.r.r.x.txt == "m"