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

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

class C:
    def __init__(self, txt: str):
        self.z: E = None
        self.y: I = None
        self.t: J = None
        self.q: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.q: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.w: H = None
        self.r: B = None
        self.x: I = None
        self.z: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.p: I = None
        self.r: I = None
        self.v: J = None
        self.z: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.u: C = None
        self.p: E = None
        self.y: F = None
        self.o: J = None
        self.q: C = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.p: A = None
        self.q: B = None
        self.o: B = None
        self.v: B = None
        self.s: C = None
        self.x: I = None
        self.t: E = None
        self.w: J = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.o: F = None
        self.y: A = None
        self.x: H = None
        self.p: G = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.q: D = None
        self.z: H = None
        self.r: C = None
        self.u: I = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.z: E = None
        self.y: I = None
        self.t: J = None
        self.q: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.q: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.w: H = None
        self.r: B = None
        self.x: I = None
        self.z: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.p: I = None
        self.r: I = None
        self.v: J = None
        self.z: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.u: C = None
        self.p: E = None
        self.y: F = None
        self.o: J = None
        self.q: C = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.p: A = None
        self.q: B = None
        self.o: B = None
        self.v: B = None
        self.s: C = None
        self.x: I = None
        self.t: E = None
        self.w: J = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.o: F = None
        self.y: A = None
        self.x: H = None
        self.p: G = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.q: D = None
        self.z: H = None
        self.r: C = None
        self.u: I = None
        self.txt = txt

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

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