class A:
    def __init__(self, txt: str):
        self.v: B = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.z: E = None
        self.q: C = None
        self.v: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.u: G = None
        self.v: H = None
        self.w: B = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: C = None
        self.p: A = None
        self.r: F = None
        self.s: E = None
        self.x: F = None
        self.u: H = None
        self.q: B = None
        self.y: E = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.x: A = None
        self.r: D = None
        self.p: D = None
        self.u: C = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.o: H = None
        self.w: F = None
        self.t: C = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.z: E = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.z: E = None
        self.q: C = None
        self.v: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.u: G = None
        self.v: H = None
        self.w: B = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: C = None
        self.p: A = None
        self.r: F = None
        self.s: E = None
        self.x: F = None
        self.u: H = None
        self.q: B = None
        self.y: E = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.x: A = None
        self.r: D = None
        self.p: D = None
        self.u: C = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.o: H = None
        self.w: F = None
        self.t: C = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.z: E = None
        self.txt = txt

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

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