class A:
    def __init__(self, txt: str):
        self.x: D = None
        self.p: I = None
        self.q: C = None
        self.u: I = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.y: H = None
        self.z: I = None
        self.x: A = None
        self.u: F = None
        self.o: C = None
        self.q: G = None
        self.t: A = None
        self.s: D = None
        self.p: C = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.v: H = None
        self.x: H = None
        self.q: E = None
        self.r: G = None
        self.txt = txt

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

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

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

class G:
    def __init__(self, txt: str):
        self.z: A = None
        self.s: H = None
        self.y: D = None
        self.w: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.p: B = None
        self.y: B = None
        self.s: C = None
        self.r: C = None
        self.x: C = None
        self.u: G = None
        self.z: I = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.y: H = None
        self.z: I = None
        self.x: A = None
        self.u: F = None
        self.o: C = None
        self.q: G = None
        self.t: A = None
        self.s: D = None
        self.p: C = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.v: H = None
        self.x: H = None
        self.q: E = None
        self.r: G = None
        self.txt = txt

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

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

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

class G:
    def __init__(self, txt: str):
        self.z: A = None
        self.s: H = None
        self.y: D = None
        self.w: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.p: B = None
        self.y: B = None
        self.s: C = None
        self.r: C = None
        self.x: C = None
        self.u: G = None
        self.z: I = None
        self.txt = txt

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

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

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