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

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

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

class D:
    def __init__(self, txt: str):
        self.y: C = None
        self.r: F = None
        self.p: A = None
        self.v: A = None
        self.x: D = None
        self.w: D = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.u: B = None
        self.r: D = None
        self.q: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.t: B = None
        self.txt = txt

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.y: C = None
        self.r: F = None
        self.p: A = None
        self.v: A = None
        self.x: D = None
        self.w: D = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.u: B = None
        self.r: D = None
        self.q: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.t: B = None
        self.txt = txt

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

b.s = g
b.r = g
b.q = g
b.z = a
b.u = k
j.q = n
j.p = b
g.w = n
g.v = j
k.y = h
k.r = e
k.p = b
k.v = b
k.x = l
k.w = l
n.u = j
n.r = l
n.q = e
e.t = j
h.w = n
h.v = j
a.q = n
a.p = b
l.y = g
l.r = e
l.p = b
l.v = b
l.x = k
l.w = k
assert e.t.q.r.p.u.w.w.v.txt == "b"