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

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

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

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

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

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

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

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

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

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

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

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

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

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

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