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

class B:
    def __init__(self, txt: str):
        self.x: A = None
        self.y: J = None
        self.w: J = None
        self.o: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.r: B = None
        self.u: I = None
        self.o: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.o: A = None
        self.x: C = None
        self.s: I = None
        self.v: B = None
        self.t: B = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.q: G = None
        self.w: I = None
        self.x: E = None
        self.v: A = None
        self.u: C = None
        self.z: A = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.z: F = None
        self.w: D = None
        self.v: B = None
        self.u: I = None
        self.t: A = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.z: C = None
        self.r: G = None
        self.w: C = None
        self.o: I = None
        self.p: C = None
        self.t: C = None
        self.q: G = None
        self.y: B = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.p: J = None
        self.v: H = None
        self.o: G = None
        self.z: C = None
        self.q: J = None
        self.u: F = None
        self.s: F = None
        self.r: F = None
        self.x: F = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.x: A = None
        self.y: J = None
        self.w: J = None
        self.o: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.r: B = None
        self.u: I = None
        self.o: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.o: A = None
        self.x: C = None
        self.s: I = None
        self.v: B = None
        self.t: B = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.q: G = None
        self.w: I = None
        self.x: E = None
        self.v: A = None
        self.u: C = None
        self.z: A = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.z: F = None
        self.w: D = None
        self.v: B = None
        self.u: I = None
        self.t: A = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.z: C = None
        self.r: G = None
        self.w: C = None
        self.o: I = None
        self.p: C = None
        self.t: C = None
        self.q: G = None
        self.y: B = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.p: J = None
        self.v: H = None
        self.o: G = None
        self.z: C = None
        self.q: J = None
        self.u: F = None
        self.s: F = None
        self.r: F = None
        self.x: F = None
        self.txt = txt

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

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

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