class A:
    def __init__(self, txt: str):
        self.w: D = None
        self.u: C = None
        self.v: B = None
        self.r: E = None
        self.q: C = None
        self.s: E = None
        self.p: G = None
        self.y: C = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.w: E = None
        self.r: A = None
        self.v: E = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.o: C = None
        self.v: I = None
        self.u: I = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.z: C = None
        self.x: C = None
        self.v: C = None
        self.q: D = None
        self.w: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.t: E = None
        self.p: H = None
        self.z: C = None
        self.u: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.y: C = None
        self.z: F = None
        self.t: C = None
        self.q: B = None
        self.p: B = None
        self.r: I = None
        self.u: B = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.u: A = None
        self.z: F = None
        self.o: G = None
        self.w: B = None
        self.r: C = None
        self.y: B = None
        self.x: D = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.w: E = None
        self.r: A = None
        self.v: E = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.o: C = None
        self.v: I = None
        self.u: I = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.z: C = None
        self.x: C = None
        self.v: C = None
        self.q: D = None
        self.w: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.t: E = None
        self.p: H = None
        self.z: C = None
        self.u: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.y: C = None
        self.z: F = None
        self.t: C = None
        self.q: B = None
        self.p: B = None
        self.r: I = None
        self.u: B = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.u: A = None
        self.z: F = None
        self.o: G = None
        self.w: B = None
        self.r: C = None
        self.y: B = None
        self.x: D = None
        self.txt = txt

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

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