class A:
    def __init__(self, txt: str):
        self.x: E = None
        self.r: D = None
        self.z: D = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.q: F = None
        self.t: C = None
        self.u: E = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.v: D = None
        self.x: B = None
        self.o: E = None
        self.w: G = None
        self.r: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: C = None
        self.z: B = None
        self.u: D = None
        self.txt = txt

e = A("e")
f = B("f")
g = C("g")
l = D("l")
b = E("b")
h = F("h")
j = G("j")
k = C("k")
a = E("a")
m = G("m")

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

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

class C:
    def __init__(self, txt: str):
        self.q: F = None
        self.t: C = None
        self.u: E = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.v: D = None
        self.x: B = None
        self.o: E = None
        self.w: G = None
        self.r: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: C = None
        self.z: B = None
        self.u: D = None
        self.txt = txt

e = A("e")
f = B("f")
g = C("g")
l = D("l")
b = E("b")
h = F("h")
j = G("j")
k = C("k")
a = E("a")
m = G("m")

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