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

class B:
    def __init__(self, txt: str):
        self.x: J = None
        self.p: G = None
        self.u: E = None
        self.w: A = None
        self.o: D = None
        self.t: C = None
        self.q: D = None
        self.r: D = None
        self.v: D = None
        self.s: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.o: D = None
        self.p: B = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.y: G = None
        self.x: G = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.s: D = None
        self.txt = txt

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

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

b = A("b")
f = B("f")
m = C("m")
c = D("c")
l = E("l")
k = F("k")
h = G("h")
g = H("g")
i = I("i")
a = J("a")

b.s = a
b.r = l
f.x = a
f.p = h
f.u = l
f.w = b
f.o = c
f.q = c
f.r = c
f.v = c
f.s = c
f.t = m
m.o = c
m.p = f
c.t = l
c.u = h
c.v = f
l.u = b
l.t = h
k.y = h
k.x = h
h.v = c
h.w = m
h.x = m
h.r = f
h.u = b
g.s = c
i.y = c
i.o = b
i.t = m
i.u = a
i.q = a
i.v = a
i.x = k
a.z = k
assert i.q.z.y.u.s.txt == "
class A:
    def __init__(self, txt: str):
        self.s: J = None
        self.r: E = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.x: J = None
        self.p: G = None
        self.u: E = None
        self.w: A = None
        self.o: D = None
        self.t: C = None
        self.q: D = None
        self.r: D = None
        self.v: D = None
        self.s: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.o: D = None
        self.p: B = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.y: G = None
        self.x: G = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.s: D = None
        self.txt = txt

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

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

b = A("b")
f = B("f")
m = C("m")
c = D("c")
l = E("l")
k = F("k")
h = G("h")
g = H("g")
i = I("i")
a = J("a")

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