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

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

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

class D:
    def __init__(self, txt: str):
        self.z: C = None
        self.s: A = None
        self.r: C = None
        self.u: B = None
        self.q: F = None
        self.x: A = None
        self.txt = txt

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

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

j = A("j")
e = B("e")
h = C("h")
b = D("b")
a = E("a")
c = F("c")
m = A("m")

j.s = m
j.z = a
j.p = h
j.w = c
e.s = b
e.u = b
h.s = c
h.z = b
h.v = j
b.z = h
b.r = h
b.s = m
b.x = m
b.u = e
b.q = c
a.w = j
a.z = e
a.t = h
c.o = e
c.s = h
c.y = m
c.x = a
m.s = j
m.z = a
m.p = h
m.w = c
assert e.u.r.z.txt == "
class A:
    def __init__(self, txt: str):
        self.s: A = None
        self.z: E = None
        self.p: C = None
        self.w: F = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.z: C = None
        self.s: A = None
        self.r: C = None
        self.u: B = None
        self.q: F = None
        self.x: A = None
        self.txt = txt

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

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

j = A("j")
e = B("e")
h = C("h")
b = D("b")
a = E("a")
c = F("c")
m = A("m")

j.s = m
j.z = a
j.p = h
j.w = c
e.s = b
e.u = b
h.s = c
h.z = b
h.v = j
b.z = h
b.r = h
b.s = m
b.x = m
b.u = e
b.q = c
a.w = j
a.z = e
a.t = h
c.o = e
c.s = h
c.y = m
c.x = a
m.s = j
m.z = a
m.p = h
m.w = c
assert e.u.r.z.txt == "b"