class A:
    def __init__(self, txt: str):
        self.r: E = None
        self.x: C = None
        self.s: C = None
        self.z: F = None
        self.v: F = None
        self.txt = txt

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

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

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

class E:
    def __init__(self, txt: str):
        self.s: F = None
        self.t: B = None
        self.y: F = None
        self.r: E = None
        self.z: F = None
        self.txt = txt

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

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

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

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

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

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

class E:
    def __init__(self, txt: str):
        self.s: F = None
        self.t: B = None
        self.y: F = None
        self.r: E = None
        self.z: F = None
        self.txt = txt

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

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

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