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

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

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

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

class E:
    def __init__(self, txt: str):
        self.t: C = None
        self.v: C = None
        self.x: C = None
        self.p: D = None
        self.u: C = None
        self.txt = txt

a = A("a")
n = B("n")
l = C("l")
m = D("m")
e = E("e")
d = D("d")
f = E("f")
b = D("b")
k = B("k")
c = B("c")

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

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

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

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

class E:
    def __init__(self, txt: str):
        self.t: C = None
        self.v: C = None
        self.x: C = None
        self.p: D = None
        self.u: C = None
        self.txt = txt

a = A("a")
n = B("n")
l = C("l")
m = D("m")
e = E("e")
d = D("d")
f = E("f")
b = D("b")
k = B("k")
c = B("c")

a.z = c
a.t = l
a.s = m
a.y = b
a.q = b
n.u = k
n.o = f
n.t = b
l.w = c
m.w = d
m.y = c
e.t = l
e.v = l
e.x = l
e.u = l
e.p = b
d.w = b
d.y = n
f.t = l
f.v = l
f.x = l
f.u = l
f.p = d
b.w = d
b.y = k
k.u = c
k.o = e
k.t = m
c.u = n
c.o = f
c.t = m
assert d.y.o.x.w.u.u.txt == "k"