class A:
    def __init__(self, txt: str):
        self.v: F = None
        self.t: J = None
        self.r: C = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.x: A = None
        self.v: C = None
        self.z: A = None
        self.s: A = None
        self.w: J = None
        self.o: F = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.q: I = None
        self.t: F = None
        self.y: A = None
        self.s: J = None
        self.v: B = None
        self.u: H = None
        self.p: G = None
        self.w: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.r: B = None
        self.z: J = None
        self.q: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.t: B = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.r: C = None
        self.t: J = None
        self.x: I = None
        self.q: E = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.p: D = None
        self.x: F = None
        self.q: G = None
        self.z: J = None
        self.s: E = None
        self.o: D = None
        self.u: G = None
        self.v: J = None
        self.w: J = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.z: G = None
        self.q: A = None
        self.p: G = None
        self.txt = txt

k = A("k")
h = B("h")
l = C("l")
d = D("d")
n = E("n")
i = F("i")
f = G("f")
j = H("j")
a = I("a")
e = J("e")

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

class B:
    def __init__(self, txt: str):
        self.x: A = None
        self.v: C = None
        self.z: A = None
        self.s: A = None
        self.w: J = None
        self.o: F = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.q: I = None
        self.t: F = None
        self.y: A = None
        self.s: J = None
        self.v: B = None
        self.u: H = None
        self.p: G = None
        self.w: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.r: B = None
        self.z: J = None
        self.q: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.t: B = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.r: C = None
        self.t: J = None
        self.x: I = None
        self.q: E = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.p: D = None
        self.x: F = None
        self.q: G = None
        self.z: J = None
        self.s: E = None
        self.o: D = None
        self.u: G = None
        self.v: J = None
        self.w: J = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.z: G = None
        self.q: A = None
        self.p: G = None
        self.txt = txt

k = A("k")
h = B("h")
l = C("l")
d = D("d")
n = E("n")
i = F("i")
f = G("f")
j = H("j")
a = I("a")
e = J("e")

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