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

class B:
    def __init__(self, txt: str):
        self.s: F = None
        self.v: G = None
        self.w: I = None
        self.r: E = None
        self.y: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.o: D = None
        self.q: A = None
        self.u: H = None
        self.x: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.p: H = None
        self.o: E = None
        self.v: A = None
        self.s: F = None
        self.x: A = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.y: B = None
        self.q: E = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.o: B = None
        self.p: G = None
        self.s: H = None
        self.w: A = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.s: F = None
        self.v: G = None
        self.w: I = None
        self.r: E = None
        self.y: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.o: D = None
        self.q: A = None
        self.u: H = None
        self.x: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.p: H = None
        self.o: E = None
        self.v: A = None
        self.s: F = None
        self.x: A = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.y: B = None
        self.q: E = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.o: B = None
        self.p: G = None
        self.s: H = None
        self.w: A = None
        self.txt = txt

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

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