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

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

class C:
    def __init__(self, txt: str):
        self.s: E = None
        self.v: E = None
        self.txt = txt

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

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

b = A("b")
k = B("k")
a = C("a")
i = D("i")
c = E("c")
n = E("n")
d = D("d")
l = B("l")
j = A("j")

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

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

class C:
    def __init__(self, txt: str):
        self.s: E = None
        self.v: E = None
        self.txt = txt

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

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

b = A("b")
k = B("k")
a = C("a")
i = D("i")
c = E("c")
n = E("n")
d = D("d")
l = B("l")
j = A("j")

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