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

class B:
    def __init__(self, txt: str):
        self.x: G = None
        self.o: F = None
        self.u: D = None
        self.v: C = None
        self.t: F = None
        self.r: E = None
        self.y: F = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.s: C = None
        self.w: F = None
        self.u: D = None
        self.v: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.u: D = None
        self.w: D = None
        self.x: E = None
        self.z: C = None
        self.s: B = None
        self.r: E = None
        self.o: G = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.p: E = None
        self.z: F = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.x: G = None
        self.o: F = None
        self.u: D = None
        self.v: C = None
        self.t: F = None
        self.r: E = None
        self.y: F = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.s: C = None
        self.w: F = None
        self.u: D = None
        self.v: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.u: D = None
        self.w: D = None
        self.x: E = None
        self.z: C = None
        self.s: B = None
        self.r: E = None
        self.o: G = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.p: E = None
        self.z: F = None
        self.txt = txt

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

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