class A:
    def __init__(self, txt: str):
        self.v: F = None
        self.o: F = None
        self.y: D = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.s: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.x: C = None
        self.o: B = None
        self.p: F = None
        self.w: A = None
        self.t: F = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.z: B = None
        self.y: E = None
        self.q: C = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.s: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.x: C = None
        self.o: B = None
        self.p: F = None
        self.w: A = None
        self.t: F = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.z: B = None
        self.y: E = None
        self.q: C = None
        self.txt = txt

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

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