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

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.w: E = None
        self.r: A = None
        self.txt = txt

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

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

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.w: E = None
        self.r: A = None
        self.txt = txt

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

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