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

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

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

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

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

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

n = A("n")
j = B("j")
e = C("e")
k = D("k")
f = E("f")
i = F("i")
m = C("m")
b = B("b")

n.w = j
j.s = b
j.x = b
j.o = n
e.t = j
e.v = n
e.w = n
e.q = n
e.r = m
k.w = n
f.w = n
f.v = b
f.t = i
f.y = e
i.y = m
i.v = n
m.t = j
m.v = n
m.w = n
m.q = n
m.r = e
b.s = j
b.x = j
b.o = n
assert i.y.r.t.o.txt == "
class A:
    def __init__(self, txt: str):
        self.w: B = None
        self.txt = txt

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

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

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

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

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

n = A("n")
j = B("j")
e = C("e")
k = D("k")
f = E("f")
i = F("i")
m = C("m")
b = B("b")

n.w = j
j.s = b
j.x = b
j.o = n
e.t = j
e.v = n
e.w = n
e.q = n
e.r = m
k.w = n
f.w = n
f.v = b
f.t = i
f.y = e
i.y = m
i.v = n
m.t = j
m.v = n
m.w = n
m.q = n
m.r = e
b.s = j
b.x = j
b.o = n
assert i.y.r.t.o.txt == "n"