class A:
    def __init__(self, txt: str):
        self.o: H = None
        self.p: E = None
        self.t: H = None
        self.x: I = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.y: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.r: F = None
        self.u: G = None
        self.z: G = None
        self.txt = txt

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

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

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

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

class H:
    def __init__(self, txt: str):
        self.o: B = None
        self.x: E = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.v: H = None
        self.o: H = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.y: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.r: F = None
        self.u: G = None
        self.z: G = None
        self.txt = txt

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

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

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

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

class H:
    def __init__(self, txt: str):
        self.o: B = None
        self.x: E = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.v: H = None
        self.o: H = None
        self.txt = txt

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

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