class A:
    def __init__(self, txt: str):
        self.s: C = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.r: A = None
        self.w: F = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.y: F = None
        self.s: B = None
        self.w: E = None
        self.r: F = None
        self.u: C = None
        self.z: A = None
        self.o: I = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.t: H = None
        self.u: I = None
        self.r: C = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.z: B = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.r: A = None
        self.w: F = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.y: F = None
        self.s: B = None
        self.w: E = None
        self.r: F = None
        self.u: C = None
        self.z: A = None
        self.o: I = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.t: H = None
        self.u: I = None
        self.r: C = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.z: B = None
        self.txt = txt

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

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