class A:
    def __init__(self, txt: str):
        self.y: D = None
        self.q: C = None
        self.u: D = None
        self.r: G = None
        self.w: B = None
        self.v: I = None
        self.z: G = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.p: J = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.t: F = None
        self.o: J = None
        self.w: J = None
        self.r: B = None
        self.z: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.z: G = None
        self.u: J = None
        self.r: A = None
        self.s: A = None
        self.y: J = None
        self.q: J = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.x: A = None
        self.r: H = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.p: E = None
        self.v: E = None
        self.o: B = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.x: C = None
        self.s: H = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.p: J = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.t: F = None
        self.o: J = None
        self.w: J = None
        self.r: B = None
        self.z: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.z: G = None
        self.u: J = None
        self.r: A = None
        self.s: A = None
        self.y: J = None
        self.q: J = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.x: A = None
        self.r: H = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.p: E = None
        self.v: E = None
        self.o: B = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.x: C = None
        self.s: H = None
        self.txt = txt

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

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