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

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

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

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

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

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

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

n.v = k
m.s = l
h.s = j
h.w = e
h.p = b
b.p = j
b.s = h
b.o = h
b.v = l
b.q = n
j.u = l
e.v = m
e.o = k
e.p = k
e.r = n
e.t = h
c.p = k
c.s = h
c.o = h
c.v = j
c.q = n
k.u = l
l.u = k
assert b.s.s.u.u.u.txt == "
class A:
    def __init__(self, txt: str):
        self.v: E = None
        self.txt = txt

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

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

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

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

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

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

n.v = k
m.s = l
h.s = j
h.w = e
h.p = b
b.p = j
b.s = h
b.o = h
b.v = l
b.q = n
j.u = l
e.v = m
e.o = k
e.p = k
e.r = n
e.t = h
c.p = k
c.s = h
c.o = h
c.v = j
c.q = n
k.u = l
l.u = k
assert b.s.s.u.u.u.txt == "l"