class A:
    def __init__(self, txt: str):
        self.o: D = None
        self.p: E = None
        self.r: F = None
        self.s: D = None
        self.y: B = None
        self.u: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.x: E = None
        self.t: F = None
        self.z: B = None
        self.s: C = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.y: A = None
        self.s: D = None
        self.p: D = None
        self.u: A = None
        self.w: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.y: C = None
        self.z: D = None
        self.q: B = None
        self.t: A = None
        self.txt = txt

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

i = A("i")
k = B("k")
b = C("b")
l = D("l")
f = E("f")
a = F("a")
g = D("g")
j = E("j")
h = B("h")

i.o = l
i.p = j
i.r = a
i.u = a
i.s = g
i.y = k
k.x = f
k.t = a
k.z = h
k.s = b
b.y = h
b.u = h
b.o = a
b.z = k
l.y = i
l.u = i
l.w = i
l.s = g
l.p = g
f.y = b
f.z = l
f.q = h
f.t = i
a.z = k
a.p = f
a.r = l
a.q = i
g.y = i
g.u = i
g.w = i
g.s = l
g.p = l
j.y = b
j.z = l
j.q = h
j.t = i
h.x = f
h.t = a
h.z = k
h.s = b
assert h.s.z.s.o.r.txt == "
class A:
    def __init__(self, txt: str):
        self.o: D = None
        self.p: E = None
        self.r: F = None
        self.s: D = None
        self.y: B = None
        self.u: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.x: E = None
        self.t: F = None
        self.z: B = None
        self.s: C = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.y: A = None
        self.s: D = None
        self.p: D = None
        self.u: A = None
        self.w: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.y: C = None
        self.z: D = None
        self.q: B = None
        self.t: A = None
        self.txt = txt

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

i = A("i")
k = B("k")
b = C("b")
l = D("l")
f = E("f")
a = F("a")
g = D("g")
j = E("j")
h = B("h")

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