class A:
    def __init__(self, txt: str):
        self.y: B = None
        self.s: F = None
        self.p: G = None
        self.r: C = None
        self.txt = txt

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

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

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

class E:
    def __init__(self, txt: str):
        self.r: F = None
        self.w: B = None
        self.p: G = None
        self.q: B = None
        self.v: F = None
        self.s: G = None
        self.y: A = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.z: B = None
        self.t: C = None
        self.o: A = None
        self.p: C = None
        self.x: E = None
        self.txt = txt

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

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

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

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

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

class E:
    def __init__(self, txt: str):
        self.r: F = None
        self.w: B = None
        self.p: G = None
        self.q: B = None
        self.v: F = None
        self.s: G = None
        self.y: A = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.z: B = None
        self.t: C = None
        self.o: A = None
        self.p: C = None
        self.x: E = None
        self.txt = txt

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

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