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

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

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

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

class E:
    def __init__(self, txt: str):
        self.o: D = None
        self.t: B = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.u: A = None
        self.y: D = None
        self.p: J = None
        self.o: H = None
        self.t: C = None
        self.v: C = None
        self.w: G = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.u: I = None
        self.p: I = None
        self.s: J = None
        self.y: F = None
        self.v: F = None
        self.q: E = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.s: J = None
        self.z: C = None
        self.v: D = None
        self.t: E = None
        self.q: E = None
        self.w: E = None
        self.p: D = None
        self.o: H = None
        self.u: B = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.o: H = None
        self.q: A = None
        self.s: B = None
        self.t: I = None
        self.z: F = None
        self.u: A = None
        self.y: I = None
        self.txt = txt

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

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

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

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

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

class E:
    def __init__(self, txt: str):
        self.o: D = None
        self.t: B = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.u: A = None
        self.y: D = None
        self.p: J = None
        self.o: H = None
        self.t: C = None
        self.v: C = None
        self.w: G = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.u: I = None
        self.p: I = None
        self.s: J = None
        self.y: F = None
        self.v: F = None
        self.q: E = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.s: J = None
        self.z: C = None
        self.v: D = None
        self.t: E = None
        self.q: E = None
        self.w: E = None
        self.p: D = None
        self.o: H = None
        self.u: B = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.o: H = None
        self.q: A = None
        self.s: B = None
        self.t: I = None
        self.z: F = None
        self.u: A = None
        self.y: I = None
        self.txt = txt

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

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