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

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

class C:
    def __init__(self, txt: str):
        self.p: C = None
        self.r: B = None
        self.w: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.t: C = None
        self.w: B = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.t: E = None
        self.q: E = None
        self.y: D = None
        self.o: A = None
        self.p: E = None
        self.x: C = None
        self.txt = txt

j = A("j")
c = B("c")
i = C("i")
a = D("a")
n = E("n")
g = F("g")
d = D("d")
f = F("f")
k = E("k")
l = C("l")

j.x = i
j.u = k
j.q = c
j.p = c
c.r = k
i.p = l
i.r = c
i.w = d
a.t = l
a.w = c
n.z = c
n.y = c
n.o = i
n.r = d
n.v = f
n.t = l
g.t = n
g.p = n
g.q = k
g.y = d
g.o = j
g.x = i
d.t = l
d.w = c
f.t = k
f.p = k
f.q = n
f.y = a
f.o = j
f.x = l
k.z = c
k.y = c
k.o = i
k.t = i
k.r = a
k.v = f
l.p = i
l.r = c
l.w = a
assert j.u.r.w.r.txt == "
class A:
    def __init__(self, txt: str):
        self.x: C = None
        self.u: E = None
        self.q: B = None
        self.p: B = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.p: C = None
        self.r: B = None
        self.w: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.t: C = None
        self.w: B = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.t: E = None
        self.q: E = None
        self.y: D = None
        self.o: A = None
        self.p: E = None
        self.x: C = None
        self.txt = txt

j = A("j")
c = B("c")
i = C("i")
a = D("a")
n = E("n")
g = F("g")
d = D("d")
f = F("f")
k = E("k")
l = C("l")

j.x = i
j.u = k
j.q = c
j.p = c
c.r = k
i.p = l
i.r = c
i.w = d
a.t = l
a.w = c
n.z = c
n.y = c
n.o = i
n.r = d
n.v = f
n.t = l
g.t = n
g.p = n
g.q = k
g.y = d
g.o = j
g.x = i
d.t = l
d.w = c
f.t = k
f.p = k
f.q = n
f.y = a
f.o = j
f.x = l
k.z = c
k.y = c
k.o = i
k.t = i
k.r = a
k.v = f
l.p = i
l.r = c
l.w = a
assert j.u.r.w.r.txt == "k"