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

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

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

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

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

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

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

class H:
    def __init__(self, txt: str):
        self.q: I = None
        self.w: A = None
        self.txt = txt

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

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

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

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

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

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

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

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

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

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

class H:
    def __init__(self, txt: str):
        self.q: I = None
        self.w: A = None
        self.txt = txt

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

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

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

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