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

class B:
    def __init__(self, txt: str):
        self.r: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.x: B = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.y: B = None
        self.q: J = None
        self.p: H = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.u: B = None
        self.z: C = None
        self.s: C = None
        self.r: H = None
        self.o: B = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.s: D = None
        self.p: E = None
        self.w: D = None
        self.u: A = None
        self.z: D = None
        self.v: I = None
        self.y: I = None
        self.r: H = None
        self.x: H = None
        self.o: I = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: I = None
        self.u: I = None
        self.o: J = None
        self.p: D = None
        self.t: H = None
        self.z: B = None
        self.r: B = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.t: B = None
        self.p: D = None
        self.q: C = None
        self.r: G = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.z: H = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.r: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.x: B = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.y: B = None
        self.q: J = None
        self.p: H = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.u: B = None
        self.z: C = None
        self.s: C = None
        self.r: H = None
        self.o: B = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.s: D = None
        self.p: E = None
        self.w: D = None
        self.u: A = None
        self.z: D = None
        self.v: I = None
        self.y: I = None
        self.r: H = None
        self.x: H = None
        self.o: I = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: I = None
        self.u: I = None
        self.o: J = None
        self.p: D = None
        self.t: H = None
        self.z: B = None
        self.r: B = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.t: B = None
        self.p: D = None
        self.q: C = None
        self.r: G = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.z: H = None
        self.txt = txt

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

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