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

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

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

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

class E:
    def __init__(self, txt: str):
        self.u: E = None
        self.v: F = None
        self.z: E = None
        self.w: E = None
        self.x: C = None
        self.o: E = None
        self.txt = txt

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

f = A("f")
h = B("h")
g = C("g")
i = D("i")
l = E("l")
a = F("a")
b = B("b")
j = A("j")
m = D("m")
n = E("n")

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

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

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

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

class E:
    def __init__(self, txt: str):
        self.u: E = None
        self.v: F = None
        self.z: E = None
        self.w: E = None
        self.x: C = None
        self.o: E = None
        self.txt = txt

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

f = A("f")
h = B("h")
g = C("g")
i = D("i")
l = E("l")
a = F("a")
b = B("b")
j = A("j")
m = D("m")
n = E("n")

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