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

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

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

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

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

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

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

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

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

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

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

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

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