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

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

class C:
    def __init__(self, txt: str):
        self.v: C = None
        self.x: A = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.v: F = None
        self.txt = txt

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.v: C = None
        self.x: A = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.v: F = None
        self.txt = txt

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

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

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