class A:
    def __init__(self, txt: str):
        self.o: I = None
        self.y: G = None
        self.p: G = None
        self.x: E = None
        self.w: D = None
        self.q: I = None
        self.z: E = None
        self.t: G = None
        self.v: D = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.r: B = None
        self.p: H = None
        self.u: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.u: G = None
        self.t: G = None
        self.o: D = None
        self.z: I = None
        self.r: D = None
        self.s: A = None
        self.q: G = None
        self.x: I = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.o: B = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.o: C = None
        self.u: B = None
        self.t: E = None
        self.y: A = None
        self.q: C = None
        self.x: A = None
        self.p: A = None
        self.v: A = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.o: I = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.t: G = None
        self.o: G = None
        self.u: D = None
        self.z: B = None
        self.p: E = None
        self.r: G = None
        self.x: H = None
        self.w: E = None
        self.txt = txt

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.r: B = None
        self.p: H = None
        self.u: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.u: G = None
        self.t: G = None
        self.o: D = None
        self.z: I = None
        self.r: D = None
        self.s: A = None
        self.q: G = None
        self.x: I = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.o: B = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.o: C = None
        self.u: B = None
        self.t: E = None
        self.y: A = None
        self.q: C = None
        self.x: A = None
        self.p: A = None
        self.v: A = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.o: I = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.t: G = None
        self.o: G = None
        self.u: D = None
        self.z: B = None
        self.p: E = None
        self.r: G = None
        self.x: H = None
        self.w: E = None
        self.txt = txt

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

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