class A:
    def __init__(self, txt: str):
        self.w: C = None
        self.r: E = None
        self.z: C = None
        self.y: B = None
        self.u: E = None
        self.x: B = None
        self.t: A = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.p: B = None
        self.o: A = None
        self.z: G = None
        self.u: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.t: B = None
        self.z: B = None
        self.o: A = None
        self.v: E = None
        self.r: F = None
        self.txt = txt

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

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

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.p: B = None
        self.o: A = None
        self.z: G = None
        self.u: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.t: B = None
        self.z: B = None
        self.o: A = None
        self.v: E = None
        self.r: F = None
        self.txt = txt

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

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

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

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

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