class A:
    def __init__(self, txt: str):
        self.v: I = None
        self.u: C = None
        self.x: I = None
        self.w: J = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.w: G = None
        self.p: E = None
        self.v: E = None
        self.x: I = None
        self.u: D = None
        self.q: E = None
        self.r: D = None
        self.t: G = None
        self.s: I = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.u: D = None
        self.o: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.z: I = None
        self.q: J = None
        self.u: C = None
        self.y: G = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.o: B = None
        self.s: B = None
        self.r: E = None
        self.w: B = None
        self.v: B = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.w: F = None
        self.t: B = None
        self.p: B = None
        self.r: H = None
        self.o: B = None
        self.x: F = None
        self.z: B = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.x: C = None
        self.p: I = None
        self.q: B = None
        self.r: I = None
        self.txt = txt

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.w: G = None
        self.p: E = None
        self.v: E = None
        self.x: I = None
        self.u: D = None
        self.q: E = None
        self.r: D = None
        self.t: G = None
        self.s: I = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.u: D = None
        self.o: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.z: I = None
        self.q: J = None
        self.u: C = None
        self.y: G = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.o: B = None
        self.s: B = None
        self.r: E = None
        self.w: B = None
        self.v: B = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.w: F = None
        self.t: B = None
        self.p: B = None
        self.r: H = None
        self.o: B = None
        self.x: F = None
        self.z: B = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.x: C = None
        self.p: I = None
        self.q: B = None
        self.r: I = None
        self.txt = txt

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

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

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

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