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

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

class E:
    def __init__(self, txt: str):
        self.r: I = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.x: C = None
        self.o: C = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.o: C = None
        self.t: I = None
        self.txt = txt

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

class J:
    def __init__(self, txt: str):
        self.r: E = None
        self.txt = txt

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

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

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

class E:
    def __init__(self, txt: str):
        self.r: I = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.x: C = None
        self.o: C = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.o: C = None
        self.t: I = None
        self.txt = txt

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

class J:
    def __init__(self, txt: str):
        self.r: E = None
        self.txt = txt

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

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