class A:
    def __init__(self, txt: str):
        self.r: G = None
        self.u: E = None
        self.t: I = None
        self.w: J = None
        self.o: I = None
        self.v: C = None
        self.z: B = None
        self.s: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.q: D = None
        self.y: A = None
        self.t: D = None
        self.z: H = None
        self.s: D = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.u: H = None
        self.p: J = None
        self.x: G = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.z: D = None
        self.p: C = None
        self.w: J = None
        self.v: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: C = None
        self.v: J = None
        self.p: I = None
        self.w: A = None
        self.t: I = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.v: A = None
        self.r: J = None
        self.o: B = None
        self.s: J = None
        self.z: E = None
        self.u: E = None
        self.y: B = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.p: H = None
        self.q: J = None
        self.s: F = None
        self.z: J = None
        self.w: H = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.t: B = None
        self.y: D = None
        self.p: C = None
        self.u: G = None
        self.o: E = None
        self.v: H = None
        self.z: B = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.q: D = None
        self.y: A = None
        self.t: D = None
        self.z: H = None
        self.s: D = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.u: H = None
        self.p: J = None
        self.x: G = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.z: D = None
        self.p: C = None
        self.w: J = None
        self.v: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: C = None
        self.v: J = None
        self.p: I = None
        self.w: A = None
        self.t: I = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.v: A = None
        self.r: J = None
        self.o: B = None
        self.s: J = None
        self.z: E = None
        self.u: E = None
        self.y: B = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.p: H = None
        self.q: J = None
        self.s: F = None
        self.z: J = None
        self.w: H = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.t: B = None
        self.y: D = None
        self.p: C = None
        self.u: G = None
        self.o: E = None
        self.v: H = None
        self.z: B = None
        self.txt = txt

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

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