class A:
    def __init__(self, txt: str):
        self.y: B = None
        self.w: E = None
        self.v: F = None
        self.p: D = None
        self.t: F = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.u: E = None
        self.p: D = None
        self.o: E = None
        self.z: C = None
        self.w: D = None
        self.y: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: C = None
        self.o: E = None
        self.p: A = None
        self.t: C = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.t: A = None
        self.w: C = None
        self.v: F = None
        self.x: C = None
        self.q: D = None
        self.r: E = None
        self.txt = txt

c = A("c")
j = B("j")
k = C("k")
l = D("l")
i = E("i")
a = F("a")
d = C("d")
h = F("h")
f = A("f")

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

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

class C:
    def __init__(self, txt: str):
        self.u: E = None
        self.p: D = None
        self.o: E = None
        self.z: C = None
        self.w: D = None
        self.y: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: C = None
        self.o: E = None
        self.p: A = None
        self.t: C = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.t: A = None
        self.w: C = None
        self.v: F = None
        self.x: C = None
        self.q: D = None
        self.r: E = None
        self.txt = txt

c = A("c")
j = B("j")
k = C("k")
l = D("l")
i = E("i")
a = F("a")
d = C("d")
h = F("h")
f = A("f")

c.y = j
c.w = i
c.v = a
c.t = a
c.p = l
j.y = h
k.u = i
k.o = i
k.y = i
k.p = l
k.w = l
k.z = d
l.v = k
l.t = k
l.o = i
l.p = f
i.t = f
i.w = f
a.t = f
a.w = k
a.v = h
a.x = d
a.q = l
a.r = i
d.u = i
d.o = i
d.y = i
d.p = l
d.w = l
d.z = k
h.t = f
h.w = d
h.x = d
h.v = a
h.q = l
h.r = i
f.y = j
f.w = i
f.v = a
f.t = a
f.p = l
assert f.y.y.t.p.t.z.z.u.txt == "i"