class A:
    def __init__(self, txt: str):
        self.v: H = None
        self.r: H = None
        self.z: F = None
        self.s: G = None
        self.p: E = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.y: E = None
        self.p: H = None
        self.s: A = None
        self.z: C = None
        self.t: A = None
        self.r: D = None
        self.x: G = None
        self.q: C = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.z: F = None
        self.q: B = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.u: A = None
        self.o: H = None
        self.r: A = None
        self.v: C = None
        self.s: G = None
        self.x: H = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: D = None
        self.q: D = None
        self.y: H = None
        self.z: D = None
        self.t: D = None
        self.x: E = None
        self.v: E = None
        self.txt = txt

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

b = A("b")
a = B("a")
e = C("e")
l = D("l")
j = E("j")
f = F("f")
h = G("h")
i = H("i")

b.v = i
b.r = i
b.z = f
b.s = h
b.p = j
a.y = j
a.p = i
a.s = b
a.t = b
a.z = e
a.q = e
a.r = l
a.x = h
e.z = f
e.q = a
l.u = a
l.s = j
l.t = b
j.v = i
j.x = e
j.z = b
j.u = l
f.u = b
f.r = b
f.o = i
f.x = i
f.v = e
f.s = h
h.s = l
h.q = l
h.z = l
h.t = l
h.y = i
h.x = j
h.v = j
i.s = j
assert e.z.s.y.txt == "
class A:
    def __init__(self, txt: str):
        self.v: H = None
        self.r: H = None
        self.z: F = None
        self.s: G = None
        self.p: E = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.y: E = None
        self.p: H = None
        self.s: A = None
        self.z: C = None
        self.t: A = None
        self.r: D = None
        self.x: G = None
        self.q: C = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.z: F = None
        self.q: B = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.u: A = None
        self.o: H = None
        self.r: A = None
        self.v: C = None
        self.s: G = None
        self.x: H = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: D = None
        self.q: D = None
        self.y: H = None
        self.z: D = None
        self.t: D = None
        self.x: E = None
        self.v: E = None
        self.txt = txt

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

b = A("b")
a = B("a")
e = C("e")
l = D("l")
j = E("j")
f = F("f")
h = G("h")
i = H("i")

b.v = i
b.r = i
b.z = f
b.s = h
b.p = j
a.y = j
a.p = i
a.s = b
a.t = b
a.z = e
a.q = e
a.r = l
a.x = h
e.z = f
e.q = a
l.u = a
l.s = j
l.t = b
j.v = i
j.x = e
j.z = b
j.u = l
f.u = b
f.r = b
f.o = i
f.x = i
f.v = e
f.s = h
h.s = l
h.q = l
h.z = l
h.t = l
h.y = i
h.x = j
h.v = j
i.s = j
assert e.z.s.y.txt == "i"