class A:
    def __init__(self, txt: str):
        self.v: B = None
        self.r: E = None
        self.x: C = None
        self.q: C = None
        self.t: C = None
        self.s: D = None
        self.txt = txt

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.y: D = None
        self.w: A = None
        self.txt = txt

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

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

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.y: D = None
        self.w: A = None
        self.txt = txt

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

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