class A:
    def __init__(self, txt: str):
        self.s: F = None
        self.w: H = None
        self.z: B = None
        self.y: D = None
        self.u: E = None
        self.t: C = None
        self.x: I = None
        self.o: F = None
        self.r: C = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.t: F = None
        self.y: D = None
        self.o: E = None
        self.u: D = None
        self.q: G = None
        self.r: G = None
        self.v: A = None
        self.z: J = None
        self.p: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: C = None
        self.q: I = None
        self.u: J = None
        self.x: J = None
        self.o: A = None
        self.z: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.y: G = None
        self.o: C = None
        self.z: I = None
        self.v: B = None
        self.q: B = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.z: F = None
        self.o: E = None
        self.t: B = None
        self.u: B = None
        self.p: H = None
        self.w: D = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.y: F = None
        self.s: A = None
        self.x: J = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.w: G = None
        self.q: D = None
        self.x: G = None
        self.o: A = None
        self.r: D = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.z: D = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.t: F = None
        self.y: D = None
        self.o: E = None
        self.u: D = None
        self.q: G = None
        self.r: G = None
        self.v: A = None
        self.z: J = None
        self.p: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: C = None
        self.q: I = None
        self.u: J = None
        self.x: J = None
        self.o: A = None
        self.z: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.y: G = None
        self.o: C = None
        self.z: I = None
        self.v: B = None
        self.q: B = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.z: F = None
        self.o: E = None
        self.t: B = None
        self.u: B = None
        self.p: H = None
        self.w: D = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.y: F = None
        self.s: A = None
        self.x: J = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.w: G = None
        self.q: D = None
        self.x: G = None
        self.o: A = None
        self.r: D = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.z: D = None
        self.txt = txt

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

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