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

class B:
    def __init__(self, txt: str):
        self.s: I = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.o: F = None
        self.q: J = None
        self.txt = txt

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

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

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

class G:
    def __init__(self, txt: str):
        self.v: B = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.o: G = None
        self.v: G = None
        self.s: G = None
        self.r: B = None
        self.y: I = None
        self.q: I = None
        self.z: D = None
        self.txt = txt

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.s: I = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.o: F = None
        self.q: J = None
        self.txt = txt

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

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

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

class G:
    def __init__(self, txt: str):
        self.v: B = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.o: G = None
        self.v: G = None
        self.s: G = None
        self.r: B = None
        self.y: I = None
        self.q: I = None
        self.z: D = None
        self.txt = txt

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

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

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

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