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

class B:
    def __init__(self, txt: str):
        self.x: A = None
        self.y: D = None
        self.w: D = None
        self.r: A = None
        self.s: G = None
        self.v: F = None
        self.u: I = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.r: H = None
        self.o: F = None
        self.p: D = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.y: D = None
        self.q: B = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.z: F = None
        self.q: B = None
        self.t: I = None
        self.x: G = None
        self.o: G = None
        self.u: A = None
        self.txt = txt

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

class J:
    def __init__(self, txt: str):
        self.p: D = None
        self.w: F = None
        self.r: E = None
        self.o: A = None
        self.y: H = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.x: A = None
        self.y: D = None
        self.w: D = None
        self.r: A = None
        self.s: G = None
        self.v: F = None
        self.u: I = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.r: H = None
        self.o: F = None
        self.p: D = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.y: D = None
        self.q: B = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.z: F = None
        self.q: B = None
        self.t: I = None
        self.x: G = None
        self.o: G = None
        self.u: A = None
        self.txt = txt

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

class J:
    def __init__(self, txt: str):
        self.p: D = None
        self.w: F = None
        self.r: E = None
        self.o: A = None
        self.y: H = None
        self.txt = txt

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

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