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

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

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

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

class E:
    def __init__(self, txt: str):
        self.z: A = None
        self.y: A = None
        self.s: D = None
        self.r: G = None
        self.p: A = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.s: F = None
        self.r: H = None
        self.w: D = None
        self.txt = txt

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

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

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

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

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

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

class E:
    def __init__(self, txt: str):
        self.z: A = None
        self.y: A = None
        self.s: D = None
        self.r: G = None
        self.p: A = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.s: F = None
        self.r: H = None
        self.w: D = None
        self.txt = txt

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

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

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