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

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

class C:
    def __init__(self, txt: str):
        self.p: F = None
        self.w: E = None
        self.z: A = None
        self.o: B = None
        self.x: A = None
        self.y: D = None
        self.txt = txt

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

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

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.p: F = None
        self.w: E = None
        self.z: A = None
        self.o: B = None
        self.x: A = None
        self.y: D = None
        self.txt = txt

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

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

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

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

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