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

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.u: A = None
        self.p: A = None
        self.s: B = None
        self.t: B = None
        self.txt = txt

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

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

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.u: A = None
        self.p: A = None
        self.s: B = None
        self.t: B = None
        self.txt = txt

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

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