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

class B:
    def __init__(self, txt: str):
        self.u: E = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.s: J = None
        self.z: H = None
        self.p: H = None
        self.x: A = None
        self.u: H = None
        self.v: I = None
        self.q: F = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.y: A = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.u: A = None
        self.s: G = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.p: H = None
        self.o: D = None
        self.q: C = None
        self.v: E = None
        self.x: H = None
        self.s: F = None
        self.w: D = None
        self.u: A = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.s: E = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.u: E = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.s: J = None
        self.z: H = None
        self.p: H = None
        self.x: A = None
        self.u: H = None
        self.v: I = None
        self.q: F = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.y: A = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.u: A = None
        self.s: G = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.p: H = None
        self.o: D = None
        self.q: C = None
        self.v: E = None
        self.x: H = None
        self.s: F = None
        self.w: D = None
        self.u: A = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.s: E = None
        self.txt = txt

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

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