class A:
    def __init__(self, txt: str):
        self.z: F = None
        self.r: G = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.x: B = None
        self.s: I = None
        self.o: A = None
        self.r: J = None
        self.y: J = None
        self.w: G = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.v: C = None
        self.t: G = None
        self.z: H = None
        self.u: A = None
        self.w: J = None
        self.o: J = None
        self.txt = txt

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

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

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

class I:
    def __init__(self, txt: str):
        self.z: A = None
        self.w: C = None
        self.q: C = None
        self.s: C = None
        self.r: F = None
        self.o: F = None
        self.t: D = None
        self.p: C = None
        self.v: A = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.o: A = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.x: B = None
        self.s: I = None
        self.o: A = None
        self.r: J = None
        self.y: J = None
        self.w: G = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.v: C = None
        self.t: G = None
        self.z: H = None
        self.u: A = None
        self.w: J = None
        self.o: J = None
        self.txt = txt

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

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

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

class I:
    def __init__(self, txt: str):
        self.z: A = None
        self.w: C = None
        self.q: C = None
        self.s: C = None
        self.r: F = None
        self.o: F = None
        self.t: D = None
        self.p: C = None
        self.v: A = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.o: A = None
        self.txt = txt

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

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