class A:
    def __init__(self, txt: str):
        self.t: C = None
        self.z: C = None
        self.u: C = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.t: I = None
        self.v: E = None
        self.w: G = None
        self.q: H = None
        self.r: H = None
        self.p: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.r: H = None
        self.w: I = None
        self.y: H = None
        self.v: F = None
        self.z: I = None
        self.q: D = None
        self.x: F = None
        self.s: I = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.u: B = None
        self.w: C = None
        self.v: E = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.x: C = None
        self.r: C = None
        self.z: H = None
        self.txt = txt

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.t: I = None
        self.v: E = None
        self.w: G = None
        self.q: H = None
        self.r: H = None
        self.p: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.r: H = None
        self.w: I = None
        self.y: H = None
        self.v: F = None
        self.z: I = None
        self.q: D = None
        self.x: F = None
        self.s: I = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.u: B = None
        self.w: C = None
        self.v: E = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.x: C = None
        self.r: C = None
        self.z: H = None
        self.txt = txt

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

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