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

class B:
    def __init__(self, txt: str):
        self.o: C = None
        self.w: C = None
        self.z: A = None
        self.q: D = None
        self.y: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.s: C = None
        self.y: D = None
        self.p: D = None
        self.t: D = None
        self.txt = txt

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

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

l = A("l")
c = B("c")
b = C("b")
i = D("i")
h = E("h")
g = B("g")
f = B("f")
m = B("m")
k = D("k")
n = C("n")

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

class B:
    def __init__(self, txt: str):
        self.o: C = None
        self.w: C = None
        self.z: A = None
        self.q: D = None
        self.y: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.s: C = None
        self.y: D = None
        self.p: D = None
        self.t: D = None
        self.txt = txt

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

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

l = A("l")
c = B("c")
b = C("b")
i = D("i")
h = E("h")
g = B("g")
f = B("f")
m = B("m")
k = D("k")
n = C("n")

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