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

class B:
    def __init__(self, txt: str):
        self.t: E = None
        self.o: A = None
        self.x: B = None
        self.y: B = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.y: A = None
        self.z: F = None
        self.w: A = None
        self.o: D = None
        self.s: C = None
        self.q: D = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.y: D = None
        self.s: A = None
        self.p: F = None
        self.u: F = None
        self.o: B = None
        self.txt = txt

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

c = A("c")
i = B("i")
n = C("n")
e = D("e")
d = E("d")
a = F("a")
g = C("g")
k = B("k")
j = F("j")

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

class B:
    def __init__(self, txt: str):
        self.t: E = None
        self.o: A = None
        self.x: B = None
        self.y: B = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.y: A = None
        self.z: F = None
        self.w: A = None
        self.o: D = None
        self.s: C = None
        self.q: D = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.y: D = None
        self.s: A = None
        self.p: F = None
        self.u: F = None
        self.o: B = None
        self.txt = txt

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

c = A("c")
i = B("i")
n = C("n")
e = D("e")
d = E("d")
a = F("a")
g = C("g")
k = B("k")
j = F("j")

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