class A:
    def __init__(self, txt: str):
        self.y: C = None
        self.v: D = None
        self.w: B = None
        self.s: A = None
        self.z: F = None
        self.t: E = None
        self.q: E = None
        self.p: B = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.p: I = None
        self.w: I = None
        self.u: H = None
        self.o: I = None
        self.q: H = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.s: B = None
        self.v: H = None
        self.u: D = None
        self.y: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.w: B = None
        self.o: B = None
        self.p: E = None
        self.s: A = None
        self.txt = txt

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

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

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.p: I = None
        self.w: I = None
        self.u: H = None
        self.o: I = None
        self.q: H = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.s: B = None
        self.v: H = None
        self.u: D = None
        self.y: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.w: B = None
        self.o: B = None
        self.p: E = None
        self.s: A = None
        self.txt = txt

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

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

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

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

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