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

class B:
    def __init__(self, txt: str):
        self.s: G = None
        self.r: C = None
        self.q: E = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.s: I = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.s: C = None
        self.z: A = None
        self.r: F = None
        self.q: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.w: G = None
        self.o: B = None
        self.x: C = None
        self.u: I = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.p: E = None
        self.u: B = None
        self.v: I = None
        self.z: D = None
        self.x: H = None
        self.t: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.v: D = None
        self.t: B = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.o: C = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.s: G = None
        self.r: C = None
        self.q: E = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.s: I = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.s: C = None
        self.z: A = None
        self.r: F = None
        self.q: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.w: G = None
        self.o: B = None
        self.x: C = None
        self.u: I = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.p: E = None
        self.u: B = None
        self.v: I = None
        self.z: D = None
        self.x: H = None
        self.t: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.v: D = None
        self.t: B = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.o: C = None
        self.txt = txt

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

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