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

class B:
    def __init__(self, txt: str):
        self.v: J = None
        self.s: D = None
        self.p: A = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.u: E = None
        self.v: A = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.s: D = None
        self.o: C = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.x: B = None
        self.txt = txt

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.v: J = None
        self.s: D = None
        self.p: A = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.u: E = None
        self.v: A = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.s: D = None
        self.o: C = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.x: B = None
        self.txt = txt

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

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

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

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