class A:
    def __init__(self, txt: str):
        self.p: F = None
        self.r: B = None
        self.x: I = None
        self.w: B = None
        self.o: C = None
        self.z: H = None
        self.txt = txt

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

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

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

class E:
    def __init__(self, txt: str):
        self.v: B = None
        self.s: H = None
        self.t: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.w: E = None
        self.z: D = None
        self.s: H = None
        self.r: I = None
        self.x: E = None
        self.v: C = None
        self.u: C = None
        self.q: I = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.w: D = None
        self.y: I = None
        self.txt = txt

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

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

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

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

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

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

class E:
    def __init__(self, txt: str):
        self.v: B = None
        self.s: H = None
        self.t: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.w: E = None
        self.z: D = None
        self.s: H = None
        self.r: I = None
        self.x: E = None
        self.v: C = None
        self.u: C = None
        self.q: I = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.w: D = None
        self.y: I = None
        self.txt = txt

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

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

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