class A:
    def __init__(self, txt: str):
        self.z: H = None
        self.y: H = None
        self.v: B = None
        self.p: I = None
        self.u: I = None
        self.t: C = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.s: C = None
        self.w: H = None
        self.o: C = None
        self.r: C = None
        self.z: A = None
        self.y: G = None
        self.t: D = None
        self.q: F = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.y: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.s: B = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.t: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.u: C = None
        self.w: D = None
        self.x: A = None
        self.y: B = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.r: F = None
        self.w: G = None
        self.y: D = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.s: C = None
        self.w: H = None
        self.o: C = None
        self.r: C = None
        self.z: A = None
        self.y: G = None
        self.t: D = None
        self.q: F = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.y: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.s: B = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.t: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.u: C = None
        self.w: D = None
        self.x: A = None
        self.y: B = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.r: F = None
        self.w: G = None
        self.y: D = None
        self.txt = txt

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

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