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

class B:
    def __init__(self, txt: str):
        self.z: B = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.w: A = None
        self.x: C = None
        self.z: F = None
        self.r: H = None
        self.u: C = None
        self.v: B = None
        self.t: G = None
        self.p: D = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.r: I = None
        self.o: D = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.z: C = None
        self.q: D = None
        self.x: B = None
        self.s: E = None
        self.v: C = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.q: G = None
        self.s: G = None
        self.p: H = None
        self.r: G = None
        self.v: C = None
        self.t: B = None
        self.y: H = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.z: B = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.w: A = None
        self.x: C = None
        self.z: F = None
        self.r: H = None
        self.u: C = None
        self.v: B = None
        self.t: G = None
        self.p: D = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.r: I = None
        self.o: D = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.z: C = None
        self.q: D = None
        self.x: B = None
        self.s: E = None
        self.v: C = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.q: G = None
        self.s: G = None
        self.p: H = None
        self.r: G = None
        self.v: C = None
        self.t: B = None
        self.y: H = None
        self.txt = txt

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

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