class A:
    def __init__(self, txt: str):
        self.v: J = None
        self.p: J = None
        self.s: B = None
        self.u: F = None
        self.t: I = None
        self.o: B = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.o: D = None
        self.w: C = None
        self.z: C = None
        self.v: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.s: D = None
        self.u: E = None
        self.x: B = None
        self.y: D = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.t: C = None
        self.x: C = None
        self.o: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.q: D = None
        self.s: H = None
        self.x: E = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.q: J = None
        self.z: H = None
        self.y: H = None
        self.v: F = None
        self.t: B = None
        self.p: G = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.o: D = None
        self.w: C = None
        self.z: C = None
        self.v: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.s: D = None
        self.u: E = None
        self.x: B = None
        self.y: D = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.t: C = None
        self.x: C = None
        self.o: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.q: D = None
        self.s: H = None
        self.x: E = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.q: J = None
        self.z: H = None
        self.y: H = None
        self.v: F = None
        self.t: B = None
        self.p: G = None
        self.txt = txt

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

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

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