class A:
    def __init__(self, txt: str):
        self.y: C = None
        self.u: H = None
        self.w: G = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.v: A = None
        self.x: H = None
        self.w: G = None
        self.y: F = None
        self.t: H = None
        self.u: B = None
        self.p: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.t: E = None
        self.s: G = None
        self.txt = txt

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

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

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

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

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.v: A = None
        self.x: H = None
        self.w: G = None
        self.y: F = None
        self.t: H = None
        self.u: B = None
        self.p: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.t: E = None
        self.s: G = None
        self.txt = txt

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

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

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

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

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

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

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