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

class B:
    def __init__(self, txt: str):
        self.z: E = None
        self.o: C = None
        self.s: C = None
        self.w: E = None
        self.p: C = None
        self.t: A = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.x: B = None
        self.r: A = None
        self.q: E = None
        self.z: C = None
        self.p: C = None
        self.y: E = None
        self.txt = txt

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

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

d = A("d")
j = B("j")
b = C("b")
h = D("h")
g = E("g")
a = F("a")
f = C("f")
l = E("l")

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

class B:
    def __init__(self, txt: str):
        self.z: E = None
        self.o: C = None
        self.s: C = None
        self.w: E = None
        self.p: C = None
        self.t: A = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.x: B = None
        self.r: A = None
        self.q: E = None
        self.z: C = None
        self.p: C = None
        self.y: E = None
        self.txt = txt

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

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

d = A("d")
j = B("j")
b = C("b")
h = D("h")
g = E("g")
a = F("a")
f = C("f")
l = E("l")

d.v = a
j.z = g
j.w = g
j.o = b
j.s = b
j.p = b
j.t = d
b.x = h
b.o = g
h.x = j
h.r = d
h.q = g
h.z = f
h.p = f
h.y = l
g.z = a
g.x = a
g.q = j
a.y = j
f.x = h
f.o = l
l.z = a
l.x = a
l.q = j
assert j.t.v.y.txt == "j"