class A:
    def __init__(self, txt: str):
        self.y: E = None
        self.x: I = None
        self.w: G = None
        self.t: G = None
        self.s: F = None
        self.u: I = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.z: H = None
        self.r: A = None
        self.w: H = None
        self.v: J = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.v: G = None
        self.q: A = None
        self.p: J = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.z: G = None
        self.v: G = None
        self.t: I = None
        self.w: E = None
        self.p: D = None
        self.q: G = None
        self.s: J = None
        self.u: E = None
        self.y: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.z: E = None
        self.x: E = None
        self.o: J = None
        self.q: A = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.x: F = None
        self.txt = txt

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.z: H = None
        self.r: A = None
        self.w: H = None
        self.v: J = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.v: G = None
        self.q: A = None
        self.p: J = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.z: G = None
        self.v: G = None
        self.t: I = None
        self.w: E = None
        self.p: D = None
        self.q: G = None
        self.s: J = None
        self.u: E = None
        self.y: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.z: E = None
        self.x: E = None
        self.o: J = None
        self.q: A = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.x: F = None
        self.txt = txt

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

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

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

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