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

class B:
    def __init__(self, txt: str):
        self.q: C = None
        self.o: J = None
        self.t: H = None
        self.w: C = None
        self.u: A = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.v: C = None
        self.r: E = None
        self.q: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.z: G = None
        self.v: G = None
        self.s: J = None
        self.t: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.r: E = None
        self.p: B = None
        self.x: C = None
        self.q: D = None
        self.o: C = None
        self.s: H = None
        self.y: A = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: F = None
        self.w: H = None
        self.z: H = None
        self.o: J = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.t: G = None
        self.x: D = None
        self.r: H = None
        self.w: H = None
        self.u: D = None
        self.o: F = None
        self.s: F = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.q: C = None
        self.o: J = None
        self.t: H = None
        self.w: C = None
        self.u: A = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.v: C = None
        self.r: E = None
        self.q: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.z: G = None
        self.v: G = None
        self.s: J = None
        self.t: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.r: E = None
        self.p: B = None
        self.x: C = None
        self.q: D = None
        self.o: C = None
        self.s: H = None
        self.y: A = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: F = None
        self.w: H = None
        self.z: H = None
        self.o: J = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.t: G = None
        self.x: D = None
        self.r: H = None
        self.w: H = None
        self.u: D = None
        self.o: F = None
        self.s: F = None
        self.txt = txt

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

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

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