class A:
    def __init__(self, txt: str):
        self.r: J = None
        self.x: I = None
        self.o: H = None
        self.p: I = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.v: J = None
        self.p: F = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.s: F = None
        self.r: E = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.u: H = None
        self.r: I = None
        self.p: I = None
        self.x: F = None
        self.s: D = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.s: D = None
        self.v: J = None
        self.w: J = None
        self.o: J = None
        self.r: A = None
        self.q: H = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.x: F = None
        self.r: H = None
        self.o: E = None
        self.t: J = None
        self.p: D = None
        self.y: J = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.w: E = None
        self.r: A = None
        self.o: I = None
        self.z: B = None
        self.q: B = None
        self.t: D = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.v: J = None
        self.p: F = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.s: F = None
        self.r: E = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.u: H = None
        self.r: I = None
        self.p: I = None
        self.x: F = None
        self.s: D = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.s: D = None
        self.v: J = None
        self.w: J = None
        self.o: J = None
        self.r: A = None
        self.q: H = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.x: F = None
        self.r: H = None
        self.o: E = None
        self.t: J = None
        self.p: D = None
        self.y: J = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.w: E = None
        self.r: A = None
        self.o: I = None
        self.z: B = None
        self.q: B = None
        self.t: D = None
        self.txt = txt

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

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