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

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

class C:
    def __init__(self, txt: str):
        self.w: G = None
        self.t: H = None
        self.z: A = None
        self.y: G = None
        self.v: H = None
        self.q: B = None
        self.txt = txt

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

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

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

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

class H:
    def __init__(self, txt: str):
        self.o: D = None
        self.u: A = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.w: G = None
        self.t: H = None
        self.z: A = None
        self.y: G = None
        self.v: H = None
        self.q: B = None
        self.txt = txt

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

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

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

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

class H:
    def __init__(self, txt: str):
        self.o: D = None
        self.u: A = None
        self.txt = txt

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

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