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

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

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

class D:
    def __init__(self, txt: str):
        self.t: B = None
        self.x: I = None
        self.y: C = None
        self.o: G = None
        self.w: B = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.y: C = None
        self.r: E = None
        self.o: A = None
        self.p: G = None
        self.s: G = None
        self.q: C = None
        self.u: D = None
        self.t: H = None
        self.x: G = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.v: J = None
        self.u: C = None
        self.r: B = None
        self.p: G = None
        self.w: A = None
        self.y: F = None
        self.txt = txt

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

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

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.t: B = None
        self.x: I = None
        self.y: C = None
        self.o: G = None
        self.w: B = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.y: C = None
        self.r: E = None
        self.o: A = None
        self.p: G = None
        self.s: G = None
        self.q: C = None
        self.u: D = None
        self.t: H = None
        self.x: G = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.v: J = None
        self.u: C = None
        self.r: B = None
        self.p: G = None
        self.w: A = None
        self.y: F = None
        self.txt = txt

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

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

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

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