class A:
    def __init__(self, txt: str):
        self.v: D = None
        self.t: E = None
        self.x: E = None
        self.o: I = None
        self.p: B = None
        self.w: E = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.q: A = None
        self.w: C = None
        self.s: E = None
        self.p: I = None
        self.z: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.z: G = None
        self.q: G = None
        self.y: J = None
        self.s: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.s: F = None
        self.q: C = None
        self.v: G = None
        self.z: F = None
        self.p: G = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.u: C = None
        self.x: J = None
        self.q: C = None
        self.t: A = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.v: B = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.q: A = None
        self.w: C = None
        self.s: E = None
        self.p: I = None
        self.z: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.z: G = None
        self.q: G = None
        self.y: J = None
        self.s: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.s: F = None
        self.q: C = None
        self.v: G = None
        self.z: F = None
        self.p: G = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.u: C = None
        self.x: J = None
        self.q: C = None
        self.t: A = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.v: B = None
        self.txt = txt

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

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

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