class A:
    def __init__(self, txt: str):
        self.r: J = None
        self.v: C = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.y: H = None
        self.v: F = None
        self.o: J = None
        self.r: G = None
        self.s: G = None
        self.txt = txt

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

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

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

class G:
    def __init__(self, txt: str):
        self.z: D = None
        self.q: D = None
        self.s: E = None
        self.y: D = None
        self.x: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.t: A = None
        self.v: C = None
        self.r: C = None
        self.u: J = None
        self.txt = txt

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

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.y: H = None
        self.v: F = None
        self.o: J = None
        self.r: G = None
        self.s: G = None
        self.txt = txt

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

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

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

class G:
    def __init__(self, txt: str):
        self.z: D = None
        self.q: D = None
        self.s: E = None
        self.y: D = None
        self.x: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.t: A = None
        self.v: C = None
        self.r: C = None
        self.u: J = None
        self.txt = txt

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

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

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

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