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

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

class C:
    def __init__(self, txt: str):
        self.x: D = None
        self.w: B = None
        self.t: C = None
        self.r: C = None
        self.y: A = None
        self.o: E = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.s: C = None
        self.o: D = None
        self.x: D = None
        self.p: C = None
        self.w: B = None
        self.t: E = None
        self.txt = txt

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

l = A("l")
k = B("k")
a = C("a")
i = D("i")
g = E("g")
f = F("f")
d = E("d")
c = C("c")
m = E("m")
b = B("b")

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

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

class C:
    def __init__(self, txt: str):
        self.x: D = None
        self.w: B = None
        self.t: C = None
        self.r: C = None
        self.y: A = None
        self.o: E = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.s: C = None
        self.o: D = None
        self.x: D = None
        self.p: C = None
        self.w: B = None
        self.t: E = None
        self.txt = txt

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

l = A("l")
k = B("k")
a = C("a")
i = D("i")
g = E("g")
f = F("f")
d = E("d")
c = C("c")
m = E("m")
b = B("b")

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