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

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

class C:
    def __init__(self, txt: str):
        self.z: C = None
        self.w: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.y: A = None
        self.r: F = None
        self.v: F = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.w: C = None
        self.x: A = None
        self.y: F = None
        self.q: C = None
        self.s: F = None
        self.txt = txt

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

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

l.o = m
l.t = m
l.y = m
l.q = i
l.w = d
l.s = d
m.p = k
m.s = k
i.z = k
i.w = l
b.y = l
b.r = d
b.v = d
c.w = i
c.q = i
c.x = l
c.y = d
c.s = d
d.q = c
d.s = c
d.p = i
d.t = k
d.w = k
j.y = l
j.r = d
j.v = d
a.y = l
a.r = d
a.v = d
k.z = i
k.w = l
g.y = l
g.r = d
g.v = d
assert d.s.x.s.q.q.z.z.w.txt == "
class A:
    def __init__(self, txt: str):
        self.o: B = None
        self.q: C = None
        self.w: F = None
        self.s: F = None
        self.t: B = None
        self.y: B = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.z: C = None
        self.w: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.y: A = None
        self.r: F = None
        self.v: F = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.w: C = None
        self.x: A = None
        self.y: F = None
        self.q: C = None
        self.s: F = None
        self.txt = txt

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

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

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