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

class B:
    def __init__(self, txt: str):
        self.x: E = None
        self.t: H = None
        self.s: A = None
        self.v: H = None
        self.w: A = None
        self.r: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.r: F = None
        self.p: B = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.q: C = None
        self.s: B = None
        self.v: E = None
        self.o: H = None
        self.x: G = None
        self.z: F = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.x: G = None
        self.t: C = None
        self.w: D = None
        self.y: B = None
        self.o: G = None
        self.s: G = None
        self.v: H = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.s: E = None
        self.z: D = None
        self.v: D = None
        self.t: C = None
        self.o: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: C = None
        self.x: E = None
        self.z: A = None
        self.y: D = None
        self.t: B = None
        self.v: C = None
        self.w: D = None
        self.r: H = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.w: A = None
        self.txt = txt

e = A("e")
h = B("h")
b = C("b")
l = D("l")
a = E("a")
m = F("m")
i = G("i")
k = H("k")

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

class B:
    def __init__(self, txt: str):
        self.x: E = None
        self.t: H = None
        self.s: A = None
        self.v: H = None
        self.w: A = None
        self.r: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.r: F = None
        self.p: B = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.q: C = None
        self.s: B = None
        self.v: E = None
        self.o: H = None
        self.x: G = None
        self.z: F = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.x: G = None
        self.t: C = None
        self.w: D = None
        self.y: B = None
        self.o: G = None
        self.s: G = None
        self.v: H = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.s: E = None
        self.z: D = None
        self.v: D = None
        self.t: C = None
        self.o: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: C = None
        self.x: E = None
        self.z: A = None
        self.y: D = None
        self.t: B = None
        self.v: C = None
        self.w: D = None
        self.r: H = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.w: A = None
        self.txt = txt

e = A("e")
h = B("h")
b = C("b")
l = D("l")
a = E("a")
m = F("m")
i = G("i")
k = H("k")

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