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

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

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

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

class E:
    def __init__(self, txt: str):
        self.w: G = None
        self.z: D = None
        self.q: B = None
        self.u: A = None
        self.t: A = None
        self.txt = txt

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

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

h = A("h")
f = B("f")
a = C("a")
e = D("e")
g = E("g")
k = F("k")
i = G("i")

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

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

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

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

class E:
    def __init__(self, txt: str):
        self.w: G = None
        self.z: D = None
        self.q: B = None
        self.u: A = None
        self.t: A = None
        self.txt = txt

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

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

h = A("h")
f = B("f")
a = C("a")
e = D("e")
g = E("g")
k = F("k")
i = G("i")

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