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

class B:
    def __init__(self, txt: str):
        self.p: A = None
        self.y: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.r: E = None
        self.u: A = None
        self.p: B = None
        self.y: A = None
        self.w: B = None
        self.t: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.r: C = None
        self.t: E = None
        self.y: F = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.p: A = None
        self.q: E = None
        self.t: A = None
        self.r: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.u: D = None
        self.o: F = None
        self.y: B = None
        self.x: B = None
        self.t: F = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.p: A = None
        self.y: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.r: E = None
        self.u: A = None
        self.p: B = None
        self.y: A = None
        self.w: B = None
        self.t: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.r: C = None
        self.t: E = None
        self.y: F = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.p: A = None
        self.q: E = None
        self.t: A = None
        self.r: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.u: D = None
        self.o: F = None
        self.y: B = None
        self.x: B = None
        self.t: F = None
        self.txt = txt

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

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