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

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

class C:
    def __init__(self, txt: str):
        self.r: D = None
        self.v: B = None
        self.o: D = None
        self.s: E = None
        self.y: F = None
        self.txt = txt

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

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

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.r: D = None
        self.v: B = None
        self.o: D = None
        self.s: E = None
        self.y: F = None
        self.txt = txt

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

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

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

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

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