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

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.z: G = None
        self.r: C = None
        self.v: B = None
        self.s: E = None
        self.y: B = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.w: B = None
        self.p: B = None
        self.x: F = None
        self.s: E = None
        self.r: E = None
        self.txt = txt

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

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

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

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.z: G = None
        self.r: C = None
        self.v: B = None
        self.s: E = None
        self.y: B = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.w: B = None
        self.p: B = None
        self.x: F = None
        self.s: E = None
        self.r: E = None
        self.txt = txt

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

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

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