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

class B:
    def __init__(self, txt: str):
        self.w: E = None
        self.o: A = None
        self.y: E = None
        self.u: D = None
        self.p: D = None
        self.s: C = None
        self.z: H = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.w: C = None
        self.v: C = None
        self.r: B = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.t: A = None
        self.x: J = None
        self.u: E = None
        self.s: J = None
        self.txt = txt

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

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.w: E = None
        self.o: A = None
        self.y: E = None
        self.u: D = None
        self.p: D = None
        self.s: C = None
        self.z: H = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.w: C = None
        self.v: C = None
        self.r: B = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.t: A = None
        self.x: J = None
        self.u: E = None
        self.s: J = None
        self.txt = txt

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

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

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

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

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