class A:
    def __init__(self, txt: str):
        self.u: F = None
        self.z: C = None
        self.x: G = None
        self.t: G = None
        self.r: G = None
        self.y: D = None
        self.w: F = None
        self.o: I = None
        self.p: I = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.v: B = None
        self.w: B = None
        self.s: I = None
        self.z: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.s: I = None
        self.u: I = None
        self.q: I = None
        self.r: A = None
        self.x: C = None
        self.t: B = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.x: E = None
        self.q: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.p: D = None
        self.u: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.u: C = None
        self.t: I = None
        self.o: G = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.x: G = None
        self.r: H = None
        self.t: H = None
        self.q: G = None
        self.o: A = None
        self.s: D = None
        self.y: F = None
        self.p: G = None
        self.w: D = None
        self.txt = txt

a = A("a")
d = B("d")
i = C("i")
f = D("f")
h = E("h")
n = F("n")
k = G("k")
e = H("e")
c = I("c")

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

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

class C:
    def __init__(self, txt: str):
        self.v: B = None
        self.w: B = None
        self.s: I = None
        self.z: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.s: I = None
        self.u: I = None
        self.q: I = None
        self.r: A = None
        self.x: C = None
        self.t: B = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.x: E = None
        self.q: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.p: D = None
        self.u: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.u: C = None
        self.t: I = None
        self.o: G = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.x: G = None
        self.r: H = None
        self.t: H = None
        self.q: G = None
        self.o: A = None
        self.s: D = None
        self.y: F = None
        self.p: G = None
        self.w: D = None
        self.txt = txt

a = A("a")
d = B("d")
i = C("i")
f = D("f")
h = E("h")
n = F("n")
k = G("k")
e = H("e")
c = I("c")

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