class A:
    def __init__(self, txt: str):
        self.u: C = None
        self.p: I = None
        self.q: F = None
        self.o: H = None
        self.r: G = None
        self.y: E = None
        self.z: D = None
        self.t: D = None
        self.w: B = None
        self.x: B = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.s: F = None
        self.o: A = None
        self.t: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.o: I = None
        self.v: A = None
        self.y: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: C = None
        self.o: E = None
        self.q: J = None
        self.z: A = None
        self.t: B = None
        self.y: I = None
        self.s: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.w: A = None
        self.s: F = None
        self.u: D = None
        self.q: G = None
        self.t: H = None
        self.v: J = None
        self.txt = txt

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

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

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

class I:
    def __init__(self, txt: str):
        self.s: F = None
        self.z: D = None
        self.o: B = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.s: F = None
        self.o: A = None
        self.t: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.o: I = None
        self.v: A = None
        self.y: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: C = None
        self.o: E = None
        self.q: J = None
        self.z: A = None
        self.t: B = None
        self.y: I = None
        self.s: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.w: A = None
        self.s: F = None
        self.u: D = None
        self.q: G = None
        self.t: H = None
        self.v: J = None
        self.txt = txt

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

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

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

class I:
    def __init__(self, txt: str):
        self.s: F = None
        self.z: D = None
        self.o: B = None
        self.txt = txt

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

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

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