class A:
    def __init__(self, txt: str):
        self.r: D = None
        self.t: C = None
        self.w: D = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.s: C = None
        self.t: E = None
        self.v: A = None
        self.x: E = None
        self.o: D = None
        self.y: F = None
        self.txt = txt

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

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

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

class F:
    def __init__(self, txt: str):
        self.p: E = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.s: C = None
        self.t: E = None
        self.v: A = None
        self.x: E = None
        self.o: D = None
        self.y: F = None
        self.txt = txt

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

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

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

class F:
    def __init__(self, txt: str):
        self.p: E = None
        self.txt = txt

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

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