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

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

class C:
    def __init__(self, txt: str):
        self.z: B = None
        self.q: F = None
        self.w: E = None
        self.o: E = None
        self.x: D = None
        self.r: B = None
        self.v: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.z: G = None
        self.v: D = None
        self.u: C = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.r: A = None
        self.t: G = None
        self.x: C = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.u: B = None
        self.x: G = None
        self.p: D = None
        self.q: A = None
        self.txt = txt

j = A("j")
f = B("f")
i = C("i")
b = D("b")
a = E("a")
e = F("e")
h = G("h")
l = G("l")
k = C("k")
d = D("d")

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

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

class C:
    def __init__(self, txt: str):
        self.z: B = None
        self.q: F = None
        self.w: E = None
        self.o: E = None
        self.x: D = None
        self.r: B = None
        self.v: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.z: G = None
        self.v: D = None
        self.u: C = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.r: A = None
        self.t: G = None
        self.x: C = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.u: B = None
        self.x: G = None
        self.p: D = None
        self.q: A = None
        self.txt = txt

j = A("j")
f = B("f")
i = C("i")
b = D("b")
a = E("a")
e = F("e")
h = G("h")
l = G("l")
k = C("k")
d = D("d")

j.s = f
j.z = e
f.y = k
f.q = j
i.z = f
i.r = f
i.q = e
i.w = a
i.o = a
i.x = d
i.v = b
b.z = l
b.v = d
b.u = k
a.y = e
e.r = j
e.t = h
e.x = i
h.u = f
h.x = l
h.p = b
h.q = j
l.u = f
l.x = h
l.p = b
l.q = j
k.z = f
k.r = f
k.q = e
k.w = a
k.o = a
k.x = d
k.v = d
d.z = l
d.v = b
d.u = i
assert j.z.r.s.q.z.t.q.z.x.w.txt == "a"