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

class B:
    def __init__(self, txt: str):
        self.y: E = None
        self.u: A = None
        self.v: D = None
        self.q: C = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.o: E = None
        self.v: E = None
        self.s: E = None
        self.y: A = None
        self.x: A = None
        self.r: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.s: C = None
        self.u: F = None
        self.q: C = None
        self.x: B = None
        self.txt = txt

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

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

c = A("c")
d = B("d")
f = C("f")
a = D("a")
l = E("l")
g = F("g")
j = B("j")
n = D("n")
i = A("i")
e = F("e")

c.x = l
c.w = l
c.u = g
c.y = n
c.o = a
d.y = l
d.u = c
d.v = n
d.q = f
f.o = l
f.v = l
f.s = l
f.r = l
f.y = c
f.x = i
a.s = f
a.q = f
a.u = g
a.x = d
l.y = e
l.x = d
g.u = n
j.y = l
j.u = i
j.v = n
j.q = f
n.s = f
n.q = f
n.u = e
n.x = j
i.x = l
i.w = l
i.u = e
i.y = n
i.o = a
e.u = a
assert l.x.y.x.v.u.u.s.y.o.txt == "
class A:
    def __init__(self, txt: str):
        self.x: E = None
        self.w: E = None
        self.u: F = None
        self.y: D = None
        self.o: D = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.y: E = None
        self.u: A = None
        self.v: D = None
        self.q: C = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.o: E = None
        self.v: E = None
        self.s: E = None
        self.y: A = None
        self.x: A = None
        self.r: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.s: C = None
        self.u: F = None
        self.q: C = None
        self.x: B = None
        self.txt = txt

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

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

c = A("c")
d = B("d")
f = C("f")
a = D("a")
l = E("l")
g = F("g")
j = B("j")
n = D("n")
i = A("i")
e = F("e")

c.x = l
c.w = l
c.u = g
c.y = n
c.o = a
d.y = l
d.u = c
d.v = n
d.q = f
f.o = l
f.v = l
f.s = l
f.r = l
f.y = c
f.x = i
a.s = f
a.q = f
a.u = g
a.x = d
l.y = e
l.x = d
g.u = n
j.y = l
j.u = i
j.v = n
j.q = f
n.s = f
n.q = f
n.u = e
n.x = j
i.x = l
i.w = l
i.u = e
i.y = n
i.o = a
e.u = a
assert l.x.y.x.v.u.u.s.y.o.txt == "a"