class A:
    def __init__(self, txt: str):
        self.t: F = None
        self.v: J = None
        self.q: E = None
        self.txt = txt

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

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

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

class E:
    def __init__(self, txt: str):
        self.o: B = None
        self.p: I = None
        self.q: D = None
        self.u: H = None
        self.w: G = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.r: B = None
        self.p: C = None
        self.w: J = None
        self.q: B = None
        self.t: C = None
        self.z: J = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.o: E = None
        self.z: F = None
        self.v: I = None
        self.y: C = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.x: G = None
        self.w: A = None
        self.t: G = None
        self.q: J = None
        self.txt = txt

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

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

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

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

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

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

class E:
    def __init__(self, txt: str):
        self.o: B = None
        self.p: I = None
        self.q: D = None
        self.u: H = None
        self.w: G = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.r: B = None
        self.p: C = None
        self.w: J = None
        self.q: B = None
        self.t: C = None
        self.z: J = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.o: E = None
        self.z: F = None
        self.v: I = None
        self.y: C = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.x: G = None
        self.w: A = None
        self.t: G = None
        self.q: J = None
        self.txt = txt

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

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

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