class A:
    def __init__(self, txt: str):
        self.w: F = None
        self.x: B = None
        self.y: C = None
        self.v: D = None
        self.r: E = None
        self.o: B = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.s: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.x: J = None
        self.p: H = None
        self.u: F = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.u: A = None
        self.q: J = None
        self.r: J = None
        self.x: F = None
        self.y: H = None
        self.o: F = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.s: J = None
        self.t: F = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.q: E = None
        self.z: C = None
        self.t: H = None
        self.u: H = None
        self.s: F = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.s: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.x: J = None
        self.p: H = None
        self.u: F = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.u: A = None
        self.q: J = None
        self.r: J = None
        self.x: F = None
        self.y: H = None
        self.o: F = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.s: J = None
        self.t: F = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.q: E = None
        self.z: C = None
        self.t: H = None
        self.u: H = None
        self.s: F = None
        self.txt = txt

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

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

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