class A:
    def __init__(self, txt: str):
        self.t: I = None
        self.w: C = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.y: F = None
        self.p: I = None
        self.t: E = None
        self.u: C = None
        self.q: A = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.r: A = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.x: I = None
        self.s: I = None
        self.o: C = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.s: I = None
        self.r: G = None
        self.o: G = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.y: F = None
        self.p: I = None
        self.t: E = None
        self.u: C = None
        self.q: A = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.r: A = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.x: I = None
        self.s: I = None
        self.o: C = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.s: I = None
        self.r: G = None
        self.o: G = None
        self.txt = txt

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

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

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