class A:
    def __init__(self, txt: str):
        self.x: I = None
        self.z: B = None
        self.s: J = None
        self.u: B = None
        self.v: J = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.z: H = None
        self.q: J = None
        self.x: B = None
        self.r: A = None
        self.t: F = None
        self.s: B = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.s: B = None
        self.y: J = None
        self.o: J = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.x: H = None
        self.w: B = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.y: G = None
        self.t: A = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.u: B = None
        self.s: I = None
        self.v: I = None
        self.p: H = None
        self.w: F = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.z: H = None
        self.q: J = None
        self.x: B = None
        self.r: A = None
        self.t: F = None
        self.s: B = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.s: B = None
        self.y: J = None
        self.o: J = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.x: H = None
        self.w: B = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.y: G = None
        self.t: A = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.u: B = None
        self.s: I = None
        self.v: I = None
        self.p: H = None
        self.w: F = None
        self.txt = txt

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

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