class A:
    def __init__(self, txt: str):
        self.y: G = None
        self.t: E = None
        self.w: H = None
        self.v: C = None
        self.u: B = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.o: G = None
        self.t: F = None
        self.p: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.x: I = None
        self.t: E = None
        self.r: E = None
        self.v: A = None
        self.o: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: B = None
        self.w: E = None
        self.z: B = None
        self.r: D = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.q: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.z: D = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.r: A = None
        self.t: E = None
        self.z: D = None
        self.u: E = None
        self.p: D = None
        self.x: A = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.o: G = None
        self.t: F = None
        self.p: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.x: I = None
        self.t: E = None
        self.r: E = None
        self.v: A = None
        self.o: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: B = None
        self.w: E = None
        self.z: B = None
        self.r: D = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.q: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.z: D = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.r: A = None
        self.t: E = None
        self.z: D = None
        self.u: E = None
        self.p: D = None
        self.x: A = None
        self.txt = txt

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

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