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

class B:
    def __init__(self, txt: str):
        self.s: G = None
        self.q: F = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.r: E = None
        self.s: H = None
        self.t: F = None
        self.v: F = None
        self.p: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.x: J = None
        self.u: E = None
        self.z: A = None
        self.p: H = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.x: B = None
        self.u: C = None
        self.v: H = None
        self.w: J = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.v: D = None
        self.s: G = None
        self.r: I = None
        self.o: A = None
        self.w: F = None
        self.u: C = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.s: H = None
        self.v: C = None
        self.t: D = None
        self.o: D = None
        self.r: J = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.s: G = None
        self.q: F = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.r: E = None
        self.s: H = None
        self.t: F = None
        self.v: F = None
        self.p: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.x: J = None
        self.u: E = None
        self.z: A = None
        self.p: H = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.x: B = None
        self.u: C = None
        self.v: H = None
        self.w: J = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.v: D = None
        self.s: G = None
        self.r: I = None
        self.o: A = None
        self.w: F = None
        self.u: C = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.s: H = None
        self.v: C = None
        self.t: D = None
        self.o: D = None
        self.r: J = None
        self.txt = txt

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

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

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