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

class B:
    def __init__(self, txt: str):
        self.v: E = None
        self.p: I = None
        self.z: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.o: F = None
        self.u: A = None
        self.x: B = None
        self.z: D = None
        self.y: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.x: E = None
        self.t: G = None
        self.p: C = None
        self.v: C = None
        self.z: H = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.w: H = None
        self.r: F = None
        self.s: A = None
        self.y: A = None
        self.x: D = None
        self.q: C = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.r: F = None
        self.p: I = None
        self.t: A = None
        self.u: C = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.w: I = None
        self.o: C = None
        self.y: I = None
        self.z: F = None
        self.t: H = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.v: E = None
        self.p: I = None
        self.z: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.o: F = None
        self.u: A = None
        self.x: B = None
        self.z: D = None
        self.y: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.x: E = None
        self.t: G = None
        self.p: C = None
        self.v: C = None
        self.z: H = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.w: H = None
        self.r: F = None
        self.s: A = None
        self.y: A = None
        self.x: D = None
        self.q: C = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.r: F = None
        self.p: I = None
        self.t: A = None
        self.u: C = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.w: I = None
        self.o: C = None
        self.y: I = None
        self.z: F = None
        self.t: H = None
        self.txt = txt

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

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