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

class B:
    def __init__(self, txt: str):
        self.r: E = None
        self.v: H = None
        self.s: C = None
        self.z: H = None
        self.x: G = None
        self.t: D = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.y: I = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.r: B = None
        self.q: J = None
        self.y: A = None
        self.v: D = None
        self.s: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.x: J = None
        self.s: D = None
        self.p: D = None
        self.v: C = None
        self.w: F = None
        self.q: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.y: D = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.r: H = None
        self.w: C = None
        self.q: D = None
        self.y: F = None
        self.z: B = None
        self.u: D = None
        self.v: D = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.r: E = None
        self.v: H = None
        self.s: C = None
        self.z: H = None
        self.x: G = None
        self.t: D = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.y: I = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.r: B = None
        self.q: J = None
        self.y: A = None
        self.v: D = None
        self.s: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.x: J = None
        self.s: D = None
        self.p: D = None
        self.v: C = None
        self.w: F = None
        self.q: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.y: D = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.r: H = None
        self.w: C = None
        self.q: D = None
        self.y: F = None
        self.z: B = None
        self.u: D = None
        self.v: D = None
        self.txt = txt

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

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

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