class A:
    def __init__(self, txt: str):
        self.y: I = None
        self.z: D = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.t: E = None
        self.y: C = None
        self.x: C = None
        self.w: F = None
        self.u: E = None
        self.z: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.y: G = None
        self.q: D = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.w: I = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.p: J = None
        self.y: B = None
        self.u: E = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.r: J = None
        self.y: J = None
        self.u: H = None
        self.t: J = None
        self.w: F = None
        self.o: G = None
        self.q: C = None
        self.p: B = None
        self.s: J = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.u: C = None
        self.r: H = None
        self.x: E = None
        self.p: G = None
        self.t: A = None
        self.q: I = None
        self.z: H = None
        self.v: E = None
        self.txt = txt

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.t: E = None
        self.y: C = None
        self.x: C = None
        self.w: F = None
        self.u: E = None
        self.z: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.y: G = None
        self.q: D = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.w: I = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.p: J = None
        self.y: B = None
        self.u: E = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.r: J = None
        self.y: J = None
        self.u: H = None
        self.t: J = None
        self.w: F = None
        self.o: G = None
        self.q: C = None
        self.p: B = None
        self.s: J = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.u: C = None
        self.r: H = None
        self.x: E = None
        self.p: G = None
        self.t: A = None
        self.q: I = None
        self.z: H = None
        self.v: E = None
        self.txt = txt

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

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