class A:
    def __init__(self, txt: str):
        self.v: D = None
        self.u: I = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.u: F = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.v: A = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.u: I = None
        self.s: C = None
        self.txt = txt

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

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.u: F = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.v: A = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.u: I = None
        self.s: C = None
        self.txt = txt

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

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

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

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

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