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

class B:
    def __init__(self, txt: str):
        self.o: G = None
        self.q: A = None
        self.z: C = None
        self.w: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.u: G = None
        self.t: B = None
        self.s: G = None
        self.x: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: F = None
        self.s: A = None
        self.o: D = None
        self.r: F = None
        self.w: E = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.x: H = None
        self.q: D = None
        self.t: H = None
        self.w: D = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.s: G = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.o: G = None
        self.q: A = None
        self.z: C = None
        self.w: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.u: G = None
        self.t: B = None
        self.s: G = None
        self.x: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: F = None
        self.s: A = None
        self.o: D = None
        self.r: F = None
        self.w: E = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.x: H = None
        self.q: D = None
        self.t: H = None
        self.w: D = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.s: G = None
        self.txt = txt

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

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