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

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

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

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

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

d = A("d")
e = B("e")
a = C("a")
c = D("c")
n = E("n")
l = E("l")
i = C("i")
g = A("g")
f = B("f")
j = A("j")

d.s = c
d.y = c
d.u = n
d.r = l
d.z = e
e.p = a
e.y = i
e.r = c
e.z = f
a.r = e
a.p = e
a.w = n
a.z = n
a.v = i
c.s = g
c.z = l
c.u = f
n.u = f
l.u = e
i.r = f
i.p = f
i.w = n
i.z = n
i.v = a
g.s = c
g.y = c
g.u = n
g.r = n
g.z = f
f.p = a
f.y = i
f.r = c
f.z = e
j.s = c
j.y = c
j.u = n
j.r = n
j.z = f
assert e.y.z.u.z.y.v.v.w.u.txt == "
class A:
    def __init__(self, txt: str):
        self.s: D = None
        self.u: E = None
        self.r: E = None
        self.y: D = None
        self.z: B = None
        self.txt = txt

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

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

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

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

d = A("d")
e = B("e")
a = C("a")
c = D("c")
n = E("n")
l = E("l")
i = C("i")
g = A("g")
f = B("f")
j = A("j")

d.s = c
d.y = c
d.u = n
d.r = l
d.z = e
e.p = a
e.y = i
e.r = c
e.z = f
a.r = e
a.p = e
a.w = n
a.z = n
a.v = i
c.s = g
c.z = l
c.u = f
n.u = f
l.u = e
i.r = f
i.p = f
i.w = n
i.z = n
i.v = a
g.s = c
g.y = c
g.u = n
g.r = n
g.z = f
f.p = a
f.y = i
f.r = c
f.z = e
j.s = c
j.y = c
j.u = n
j.r = n
j.z = f
assert e.y.z.u.z.y.v.v.w.u.txt == "f"