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

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

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

class D:
    def __init__(self, txt: str):
        self.t: B = None
        self.q: C = None
        self.o: I = None
        self.u: A = None
        self.z: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: A = None
        self.p: D = None
        self.v: J = None
        self.z: G = None
        self.y: J = None
        self.s: D = None
        self.t: J = None
        self.txt = txt

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

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

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

class I:
    def __init__(self, txt: str):
        self.w: B = None
        self.z: H = None
        self.x: A = None
        self.p: C = None
        self.q: B = None
        self.y: B = None
        self.txt = txt

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

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.t: B = None
        self.q: C = None
        self.o: I = None
        self.u: A = None
        self.z: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: A = None
        self.p: D = None
        self.v: J = None
        self.z: G = None
        self.y: J = None
        self.s: D = None
        self.t: J = None
        self.txt = txt

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

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

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

class I:
    def __init__(self, txt: str):
        self.w: B = None
        self.z: H = None
        self.x: A = None
        self.p: C = None
        self.q: B = None
        self.y: B = None
        self.txt = txt

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

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

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