class A:
    def __init__(self, txt: str):
        self.v: B = None
        self.y: F = None
        self.x: H = None
        self.s: H = None
        self.o: J = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.z: I = None
        self.t: I = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.s: E = None
        self.x: H = None
        self.y: B = None
        self.v: A = None
        self.q: I = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.z: F = None
        self.q: B = None
        self.u: A = None
        self.s: I = None
        self.r: H = None
        self.w: I = None
        self.t: G = None
        self.y: I = None
        self.p: D = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.q: D = None
        self.z: B = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.o: A = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.t: C = None
        self.r: E = None
        self.w: E = None
        self.z: J = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.x: I = None
        self.o: B = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.z: I = None
        self.t: I = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.s: E = None
        self.x: H = None
        self.y: B = None
        self.v: A = None
        self.q: I = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.z: F = None
        self.q: B = None
        self.u: A = None
        self.s: I = None
        self.r: H = None
        self.w: I = None
        self.t: G = None
        self.y: I = None
        self.p: D = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.q: D = None
        self.z: B = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.o: A = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.t: C = None
        self.r: E = None
        self.w: E = None
        self.z: J = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.x: I = None
        self.o: B = None
        self.txt = txt

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

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