class A:
    def __init__(self, txt: str):
        self.w: I = None
        self.s: C = None
        self.q: B = None
        self.y: E = None
        self.p: G = None
        self.txt = txt

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

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

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

class E:
    def __init__(self, txt: str):
        self.t: B = None
        self.w: I = None
        self.x: I = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.s: D = None
        self.p: A = None
        self.x: G = None
        self.t: I = None
        self.w: D = None
        self.txt = txt

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

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

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

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

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

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

class E:
    def __init__(self, txt: str):
        self.t: B = None
        self.w: I = None
        self.x: I = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.s: D = None
        self.p: A = None
        self.x: G = None
        self.t: I = None
        self.w: D = None
        self.txt = txt

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

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

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