class A:
    def __init__(self, txt: str):
        self.o: C = None
        self.w: C = None
        self.v: D = None
        self.p: F = None
        self.u: H = None
        self.r: D = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.s: A = None
        self.x: F = None
        self.z: F = None
        self.v: D = None
        self.t: C = None
        self.q: D = None
        self.p: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.z: E = None
        self.v: I = None
        self.o: H = None
        self.s: H = None
        self.q: I = None
        self.p: E = None
        self.x: A = None
        self.txt = txt

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

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

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

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

class I:
    def __init__(self, txt: str):
        self.x: B = None
        self.u: B = None
        self.r: C = None
        self.p: H = None
        self.o: C = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.s: A = None
        self.x: F = None
        self.z: F = None
        self.v: D = None
        self.t: C = None
        self.q: D = None
        self.p: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.z: E = None
        self.v: I = None
        self.o: H = None
        self.s: H = None
        self.q: I = None
        self.p: E = None
        self.x: A = None
        self.txt = txt

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

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

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

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

class I:
    def __init__(self, txt: str):
        self.x: B = None
        self.u: B = None
        self.r: C = None
        self.p: H = None
        self.o: C = None
        self.txt = txt

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

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