class A:
    def __init__(self, txt: str):
        self.z: E = None
        self.t: D = None
        self.x: J = None
        self.r: F = None
        self.o: E = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.v: H = None
        self.t: I = None
        self.y: H = None
        self.r: I = None
        self.o: D = None
        self.z: E = None
        self.q: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.r: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.r: B = None
        self.txt = txt

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

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

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

class H:
    def __init__(self, txt: str):
        self.p: J = None
        self.q: F = None
        self.v: A = None
        self.w: J = None
        self.z: G = None
        self.o: F = None
        self.y: G = None
        self.x: D = None
        self.txt = txt

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.v: H = None
        self.t: I = None
        self.y: H = None
        self.r: I = None
        self.o: D = None
        self.z: E = None
        self.q: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.r: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.r: B = None
        self.txt = txt

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

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

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

class H:
    def __init__(self, txt: str):
        self.p: J = None
        self.q: F = None
        self.v: A = None
        self.w: J = None
        self.z: G = None
        self.o: F = None
        self.y: G = None
        self.x: D = None
        self.txt = txt

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

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

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

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