class A:
    def __init__(self, txt: str):
        self.y: B = None
        self.x: D = None
        self.txt = txt

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.v: I = None
        self.u: G = None
        self.t: H = None
        self.x: A = None
        self.q: B = None
        self.s: I = None
        self.w: A = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.t: E = None
        self.y: I = None
        self.u: D = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.w: G = None
        self.p: F = None
        self.r: E = None
        self.o: H = None
        self.txt = txt

b = A("b")
l = B("l")
n = C("n")
e = D("e")
j = E("j")
f = F("f")
k = G("k")
g = H("g")
a = I("a")

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

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.v: I = None
        self.u: G = None
        self.t: H = None
        self.x: A = None
        self.q: B = None
        self.s: I = None
        self.w: A = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.t: E = None
        self.y: I = None
        self.u: D = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.w: G = None
        self.p: F = None
        self.r: E = None
        self.o: H = None
        self.txt = txt

b = A("b")
l = B("l")
n = C("n")
e = D("e")
j = E("j")
f = F("f")
k = G("k")
g = H("g")
a = I("a")

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