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

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.x: I = None
        self.u: C = None
        self.s: H = None
        self.v: I = None
        self.y: E = None
        self.txt = txt

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

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

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

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

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

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.x: I = None
        self.u: C = None
        self.s: H = None
        self.v: I = None
        self.y: E = None
        self.txt = txt

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

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

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

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

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