class A:
    def __init__(self, txt: str):
        self.s: C = None
        self.y: D = None
        self.x: B = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.y: D = None
        self.z: C = None
        self.w: H = None
        self.r: A = None
        self.o: B = None
        self.v: A = None
        self.p: F = None
        self.u: C = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.r: G = None
        self.x: H = None
        self.t: F = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.v: E = None
        self.u: G = None
        self.s: A = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.w: H = None
        self.s: F = None
        self.o: F = None
        self.x: D = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.y: D = None
        self.z: C = None
        self.w: H = None
        self.r: A = None
        self.o: B = None
        self.v: A = None
        self.p: F = None
        self.u: C = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.r: G = None
        self.x: H = None
        self.t: F = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.v: E = None
        self.u: G = None
        self.s: A = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.w: H = None
        self.s: F = None
        self.o: F = None
        self.x: D = None
        self.txt = txt

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

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

l.s = f
l.y = k
l.x = m
e.y = k
e.z = f
e.u = f
e.w = n
e.r = l
e.v = l
e.o = m
e.p = b
f.w = b
f.o = l
f.t = n
f.p = a
k.r = a
k.x = n
k.t = b
d.o = f
d.v = f
b.v = d
b.u = a
b.s = l
a.w = j
a.s = b
a.o = b
a.x = k
j.v = e
n.v = e
m.y = k
m.z = f
m.u = f
m.w = n
m.r = l
m.v = l
m.o = e
m.p = b
assert l.y.r.s.txt == "b"