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

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

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

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

class E:
    def __init__(self, txt: str):
        self.o: D = None
        self.r: B = None
        self.w: B = None
        self.z: A = None
        self.txt = txt

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

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

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

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

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

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

class E:
    def __init__(self, txt: str):
        self.o: D = None
        self.r: B = None
        self.w: B = None
        self.z: A = None
        self.txt = txt

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

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

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