class A:
    def __init__(self, txt: str):
        self.q: I = None
        self.s: E = None
        self.z: I = None
        self.v: C = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.p: G = None
        self.y: H = None
        self.w: A = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.v: A = None
        self.u: J = None
        self.r: D = None
        self.w: J = None
        self.z: J = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.v: J = None
        self.u: H = None
        self.o: A = None
        self.t: H = None
        self.r: A = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.v: A = None
        self.x: J = None
        self.q: B = None
        self.p: C = None
        self.z: C = None
        self.w: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.o: E = None
        self.x: C = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.r: C = None
        self.x: E = None
        self.q: G = None
        self.z: C = None
        self.y: J = None
        self.o: E = None
        self.t: G = None
        self.s: C = None
        self.v: J = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.p: G = None
        self.y: H = None
        self.w: A = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.v: A = None
        self.u: J = None
        self.r: D = None
        self.w: J = None
        self.z: J = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.v: J = None
        self.u: H = None
        self.o: A = None
        self.t: H = None
        self.r: A = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.v: A = None
        self.x: J = None
        self.q: B = None
        self.p: C = None
        self.z: C = None
        self.w: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.o: E = None
        self.x: C = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.r: C = None
        self.x: E = None
        self.q: G = None
        self.z: C = None
        self.y: J = None
        self.o: E = None
        self.t: G = None
        self.s: C = None
        self.v: J = None
        self.txt = txt

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

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

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