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

class B:
    def __init__(self, txt: str):
        self.r: F = None
        self.y: D = None
        self.x: A = None
        self.t: A = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.v: F = None
        self.y: J = None
        self.p: C = None
        self.r: E = None
        self.o: B = None
        self.q: E = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.q: I = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.w: J = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.r: F = None
        self.y: D = None
        self.x: A = None
        self.t: A = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.v: F = None
        self.y: J = None
        self.p: C = None
        self.r: E = None
        self.o: B = None
        self.q: E = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.q: I = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.w: J = None
        self.txt = txt

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

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

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