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

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

class C:
    def __init__(self, txt: str):
        self.y: C = None
        self.r: A = None
        self.z: B = None
        self.x: E = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.r: D = None
        self.z: E = None
        self.p: C = None
        self.t: B = None
        self.txt = txt

c = A("c")
k = B("k")
g = C("g")
e = D("e")
h = E("h")
l = A("l")
d = C("d")
f = E("f")
j = D("j")

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

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

class C:
    def __init__(self, txt: str):
        self.y: C = None
        self.r: A = None
        self.z: B = None
        self.x: E = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.r: D = None
        self.z: E = None
        self.p: C = None
        self.t: B = None
        self.txt = txt

c = A("c")
k = B("k")
g = C("g")
e = D("e")
h = E("h")
l = A("l")
d = C("d")
f = E("f")
j = D("j")

c.u = h
c.y = j
k.s = c
g.y = d
g.r = c
g.z = k
g.x = f
e.w = l
e.q = d
e.o = d
e.u = k
e.s = g
h.r = e
h.z = f
h.p = g
h.t = k
l.u = h
l.y = j
d.y = g
d.r = l
d.z = k
d.x = f
f.r = e
f.z = h
f.p = d
f.t = k
j.w = c
j.q = g
j.o = g
j.s = g
j.u = k
assert e.o.y.y.r.y.u.s.txt == "c"