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

class B:
    def __init__(self, txt: str):
        self.p: C = None
        self.o: A = None
        self.r: A = None
        self.t: E = None
        self.w: C = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: H = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.u: J = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.z: B = None
        self.o: B = None
        self.x: I = None
        self.q: C = None
        self.w: I = None
        self.v: C = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.r: C = None
        self.z: D = None
        self.w: D = None
        self.txt = txt

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.p: C = None
        self.o: A = None
        self.r: A = None
        self.t: E = None
        self.w: C = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: H = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.u: J = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.z: B = None
        self.o: B = None
        self.x: I = None
        self.q: C = None
        self.w: I = None
        self.v: C = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.r: C = None
        self.z: D = None
        self.w: D = None
        self.txt = txt

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

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

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

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