class A:
    def __init__(self, txt: str):
        self.x: A = None
        self.r: E = None
        self.u: F = None
        self.t: A = None
        self.o: A = None
        self.w: E = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.w: B = None
        self.z: E = None
        self.u: F = None
        self.p: C = None
        self.r: C = None
        self.s: F = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.t: D = None
        self.txt = txt

g = A("g")
j = B("j")
c = C("c")
l = D("l")
a = E("a")
n = F("n")
f = A("f")
k = D("k")
b = C("b")
e = F("e")

g.x = f
g.t = f
g.o = f
g.r = a
g.w = a
g.u = e
j.s = c
j.w = b
j.y = e
c.s = n
c.r = e
c.x = j
l.w = j
l.z = a
l.u = n
l.p = b
l.r = b
l.s = e
a.o = l
a.x = f
n.t = k
f.x = g
f.t = g
f.o = g
f.r = a
f.w = a
f.u = n
k.w = j
k.z = a
k.u = e
k.p = b
k.r = b
k.s = n
b.s = e
b.r = e
b.x = j
e.t = k
assert k.s.t.z.o.z.o.u.t.txt == "
class A:
    def __init__(self, txt: str):
        self.x: A = None
        self.r: E = None
        self.u: F = None
        self.t: A = None
        self.o: A = None
        self.w: E = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.w: B = None
        self.z: E = None
        self.u: F = None
        self.p: C = None
        self.r: C = None
        self.s: F = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.t: D = None
        self.txt = txt

g = A("g")
j = B("j")
c = C("c")
l = D("l")
a = E("a")
n = F("n")
f = A("f")
k = D("k")
b = C("b")
e = F("e")

g.x = f
g.t = f
g.o = f
g.r = a
g.w = a
g.u = e
j.s = c
j.w = b
j.y = e
c.s = n
c.r = e
c.x = j
l.w = j
l.z = a
l.u = n
l.p = b
l.r = b
l.s = e
a.o = l
a.x = f
n.t = k
f.x = g
f.t = g
f.o = g
f.r = a
f.w = a
f.u = n
k.w = j
k.z = a
k.u = e
k.p = b
k.r = b
k.s = n
b.s = e
b.r = e
b.x = j
e.t = k
assert k.s.t.z.o.z.o.u.t.txt == "k"