class A:
    def __init__(self, txt: str):
        self.o: B = None
        self.y: E = None
        self.x: G = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.v: G = None
        self.s: I = None
        self.p: G = None
        self.q: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: J = None
        self.v: E = None
        self.u: I = None
        self.o: H = None
        self.s: J = None
        self.w: H = None
        self.q: J = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.q: B = None
        self.w: G = None
        self.r: I = None
        self.p: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.t: A = None
        self.z: C = None
        self.q: A = None
        self.v: A = None
        self.y: A = None
        self.s: A = None
        self.u: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.z: H = None
        self.t: G = None
        self.o: C = None
        self.r: C = None
        self.p: H = None
        self.y: E = None
        self.q: I = None
        self.x: C = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.w: A = None
        self.t: J = None
        self.s: J = None
        self.p: F = None
        self.z: I = None
        self.txt = txt

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.v: G = None
        self.s: I = None
        self.p: G = None
        self.q: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: J = None
        self.v: E = None
        self.u: I = None
        self.o: H = None
        self.s: J = None
        self.w: H = None
        self.q: J = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.q: B = None
        self.w: G = None
        self.r: I = None
        self.p: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.t: A = None
        self.z: C = None
        self.q: A = None
        self.v: A = None
        self.y: A = None
        self.s: A = None
        self.u: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.z: H = None
        self.t: G = None
        self.o: C = None
        self.r: C = None
        self.p: H = None
        self.y: E = None
        self.q: I = None
        self.x: C = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.w: A = None
        self.t: J = None
        self.s: J = None
        self.p: F = None
        self.z: I = None
        self.txt = txt

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

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

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

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