class A:
    def __init__(self, txt: str):
        self.w: A = None
        self.z: B = None
        self.s: D = None
        self.r: C = None
        self.t: D = None
        self.v: F = None
        self.txt = txt

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

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

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

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

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

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

i.w = l
i.z = d
i.s = k
i.t = k
i.r = j
i.v = a
d.y = n
d.o = a
d.z = a
d.s = l
d.q = i
d.u = j
j.q = l
j.r = k
j.u = k
j.o = n
k.s = e
k.x = i
k.o = a
e.u = d
e.r = d
e.o = d
n.q = a
n.v = a
n.s = a
n.x = l
n.o = k
a.q = n
a.v = n
a.s = n
a.x = l
a.o = k
l.w = i
l.z = d
l.s = k
l.t = k
l.r = j
l.v = a
assert d.q.w.z.q.v.x.v.x.txt == "
class A:
    def __init__(self, txt: str):
        self.w: A = None
        self.z: B = None
        self.s: D = None
        self.r: C = None
        self.t: D = None
        self.v: F = None
        self.txt = txt

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

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

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

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

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

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

i.w = l
i.z = d
i.s = k
i.t = k
i.r = j
i.v = a
d.y = n
d.o = a
d.z = a
d.s = l
d.q = i
d.u = j
j.q = l
j.r = k
j.u = k
j.o = n
k.s = e
k.x = i
k.o = a
e.u = d
e.r = d
e.o = d
n.q = a
n.v = a
n.s = a
n.x = l
n.o = k
a.q = n
a.v = n
a.s = n
a.x = l
a.o = k
l.w = i
l.z = d
l.s = k
l.t = k
l.r = j
l.v = a
assert d.q.w.z.q.v.x.v.x.txt == "l"