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

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

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

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

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

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

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

class H:
    def __init__(self, txt: str):
        self.u: D = None
        self.x: C = None
        self.t: J = None
        self.txt = txt

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

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

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

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

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

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

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

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

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

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

class H:
    def __init__(self, txt: str):
        self.u: D = None
        self.x: C = None
        self.t: J = None
        self.txt = txt

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

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

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

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