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

class B:
    def __init__(self, txt: str):
        self.v: C = None
        self.u: I = None
        self.w: G = None
        self.y: H = None
        self.o: C = None
        self.s: D = None
        self.t: C = None
        self.x: A = None
        self.z: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: D = None
        self.w: G = None
        self.z: G = None
        self.r: G = None
        self.v: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.y: H = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: G = None
        self.v: G = None
        self.q: B = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.t: D = None
        self.r: B = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.x: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.s: C = None
        self.t: B = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.p: D = None
        self.z: A = None
        self.o: E = None
        self.w: E = None
        self.y: E = None
        self.t: C = None
        self.x: F = None
        self.txt = txt

d = A("d")
i = B("i")
e = C("e")
c = D("c")
b = E("b")
l = F("l")
h = G("h")
j = H("j")
k = I("k")

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

class B:
    def __init__(self, txt: str):
        self.v: C = None
        self.u: I = None
        self.w: G = None
        self.y: H = None
        self.o: C = None
        self.s: D = None
        self.t: C = None
        self.x: A = None
        self.z: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: D = None
        self.w: G = None
        self.z: G = None
        self.r: G = None
        self.v: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.y: H = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: G = None
        self.v: G = None
        self.q: B = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.t: D = None
        self.r: B = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.x: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.s: C = None
        self.t: B = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.p: D = None
        self.z: A = None
        self.o: E = None
        self.w: E = None
        self.y: E = None
        self.t: C = None
        self.x: F = None
        self.txt = txt

d = A("d")
i = B("i")
e = C("e")
c = D("c")
b = E("b")
l = F("l")
h = G("h")
j = H("j")
k = I("k")

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