class A:
    def __init__(self, txt: str):
        self.t: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.s: J = None
        self.z: J = None
        self.y: C = None
        self.v: A = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.v: J = None
        self.p: F = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.t: J = None
        self.x: J = None
        self.o: D = None
        self.y: J = None
        self.u: B = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.t: J = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: E = None
        self.u: C = None
        self.t: B = None
        self.w: C = None
        self.v: E = None
        self.z: D = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.o: D = None
        self.t: B = None
        self.u: E = None
        self.x: F = None
        self.v: A = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.s: J = None
        self.z: J = None
        self.y: C = None
        self.v: A = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.v: J = None
        self.p: F = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.t: J = None
        self.x: J = None
        self.o: D = None
        self.y: J = None
        self.u: B = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.t: J = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: E = None
        self.u: C = None
        self.t: B = None
        self.w: C = None
        self.v: E = None
        self.z: D = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.o: D = None
        self.t: B = None
        self.u: E = None
        self.x: F = None
        self.v: A = None
        self.txt = txt

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

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

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