class A:
    def __init__(self, txt: str):
        self.z: G = None
        self.y: H = None
        self.o: E = None
        self.x: H = None
        self.s: I = None
        self.txt = txt

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

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

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

class E:
    def __init__(self, txt: str):
        self.x: F = None
        self.y: F = None
        self.s: A = None
        self.r: I = None
        self.t: G = None
        self.v: F = None
        self.p: D = None
        self.u: I = None
        self.txt = txt

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

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

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

class I:
    def __init__(self, txt: str):
        self.w: B = None
        self.r: H = None
        self.s: F = None
        self.t: H = None
        self.v: E = None
        self.u: E = None
        self.x: B = None
        self.q: F = None
        self.txt = txt

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

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

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

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

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

class E:
    def __init__(self, txt: str):
        self.x: F = None
        self.y: F = None
        self.s: A = None
        self.r: I = None
        self.t: G = None
        self.v: F = None
        self.p: D = None
        self.u: I = None
        self.txt = txt

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

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

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

class I:
    def __init__(self, txt: str):
        self.w: B = None
        self.r: H = None
        self.s: F = None
        self.t: H = None
        self.v: E = None
        self.u: E = None
        self.x: B = None
        self.q: F = None
        self.txt = txt

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

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