class A:
    def __init__(self, txt: str):
        self.o: C = None
        self.r: G = None
        self.x: I = None
        self.u: G = None
        self.v: C = None
        self.w: J = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.r: I = None
        self.o: A = None
        self.p: I = None
        self.q: B = None
        self.w: G = None
        self.v: J = None
        self.s: F = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.r: E = None
        self.u: H = None
        self.t: G = None
        self.v: H = None
        self.x: J = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.x: C = None
        self.z: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.u: E = None
        self.s: D = None
        self.o: E = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.v: A = None
        self.x: C = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.p: F = None
        self.s: E = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.r: I = None
        self.o: A = None
        self.p: I = None
        self.q: B = None
        self.w: G = None
        self.v: J = None
        self.s: F = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.r: E = None
        self.u: H = None
        self.t: G = None
        self.v: H = None
        self.x: J = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.x: C = None
        self.z: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.u: E = None
        self.s: D = None
        self.o: E = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.v: A = None
        self.x: C = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.p: F = None
        self.s: E = None
        self.txt = txt

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

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