class A:
    def __init__(self, txt: str):
        self.o: I = None
        self.y: C = None
        self.v: H = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.r: C = None
        self.y: C = None
        self.q: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.q: F = None
        self.t: H = None
        self.o: B = None
        self.w: B = None
        self.r: B = None
        self.y: H = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: B = None
        self.u: A = None
        self.x: D = None
        self.z: I = None
        self.p: E = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.y: B = None
        self.p: I = None
        self.z: A = None
        self.txt = txt

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

f = A("f")
b = B("b")
h = C("h")
m = D("m")
a = E("a")
k = F("k")
l = G("l")
c = H("c")
d = I("d")
i = B("i")

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

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

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

class D:
    def __init__(self, txt: str):
        self.r: C = None
        self.y: C = None
        self.q: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.q: F = None
        self.t: H = None
        self.o: B = None
        self.w: B = None
        self.r: B = None
        self.y: H = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: B = None
        self.u: A = None
        self.x: D = None
        self.z: I = None
        self.p: E = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.y: B = None
        self.p: I = None
        self.z: A = None
        self.txt = txt

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

f = A("f")
b = B("b")
h = C("h")
m = D("m")
a = E("a")
k = F("k")
l = G("l")
c = H("c")
d = I("d")
i = B("i")

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