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

class B:
    def __init__(self, txt: str):
        self.y: C = None
        self.v: A = None
        self.q: F = None
        self.u: D = None
        self.z: E = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.x: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.r: B = None
        self.v: B = None
        self.t: B = None
        self.z: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.u: G = None
        self.v: A = None
        self.x: G = None
        self.s: E = None
        self.y: B = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.y: C = None
        self.u: A = None
        self.o: F = None
        self.q: A = None
        self.v: F = None
        self.z: A = None
        self.p: A = None
        self.txt = txt

i = A("i")
e = B("e")
n = C("n")
c = D("c")
f = E("f")
k = F("k")
a = G("a")
l = F("l")

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

class B:
    def __init__(self, txt: str):
        self.y: C = None
        self.v: A = None
        self.q: F = None
        self.u: D = None
        self.z: E = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.x: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.r: B = None
        self.v: B = None
        self.t: B = None
        self.z: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.u: G = None
        self.v: A = None
        self.x: G = None
        self.s: E = None
        self.y: B = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.y: C = None
        self.u: A = None
        self.o: F = None
        self.q: A = None
        self.v: F = None
        self.z: A = None
        self.p: A = None
        self.txt = txt

i = A("i")
e = B("e")
n = C("n")
c = D("c")
f = E("f")
k = F("k")
a = G("a")
l = F("l")

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