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

class B:
    def __init__(self, txt: str):
        self.x: H = None
        self.w: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.y: D = None
        self.u: G = None
        self.r: H = None
        self.v: B = None
        self.p: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.q: A = None
        self.w: H = None
        self.o: E = None
        self.x: E = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.t: C = None
        self.z: E = None
        self.p: C = None
        self.u: H = None
        self.r: E = None
        self.y: C = None
        self.w: A = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.x: E = None
        self.t: F = None
        self.q: F = None
        self.z: C = None
        self.u: E = None
        self.v: C = None
        self.o: B = None
        self.y: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.o: F = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.x: H = None
        self.w: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.y: D = None
        self.u: G = None
        self.r: H = None
        self.v: B = None
        self.p: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.q: A = None
        self.w: H = None
        self.o: E = None
        self.x: E = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.t: C = None
        self.z: E = None
        self.p: C = None
        self.u: H = None
        self.r: E = None
        self.y: C = None
        self.w: A = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.x: E = None
        self.t: F = None
        self.q: F = None
        self.z: C = None
        self.u: E = None
        self.v: C = None
        self.o: B = None
        self.y: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.o: F = None
        self.txt = txt

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

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