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

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

class C:
    def __init__(self, txt: str):
        self.p: C = None
        self.t: F = None
        self.v: D = None
        self.q: H = None
        self.z: I = None
        self.r: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.s: A = None
        self.u: B = None
        self.p: H = None
        self.w: F = None
        self.y: H = None
        self.txt = txt

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

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

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

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

class I:
    def __init__(self, txt: str):
        self.z: B = None
        self.t: C = None
        self.w: A = None
        self.r: D = None
        self.y: F = None
        self.u: D = None
        self.q: H = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.p: C = None
        self.t: F = None
        self.v: D = None
        self.q: H = None
        self.z: I = None
        self.r: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.s: A = None
        self.u: B = None
        self.p: H = None
        self.w: F = None
        self.y: H = None
        self.txt = txt

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

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

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

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

class I:
    def __init__(self, txt: str):
        self.z: B = None
        self.t: C = None
        self.w: A = None
        self.r: D = None
        self.y: F = None
        self.u: D = None
        self.q: H = None
        self.txt = txt

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

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