class A:
    def __init__(self, txt: str):
        self.o: F = None
        self.txt = txt

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.r: G = None
        self.s: H = None
        self.v: G = None
        self.q: D = None
        self.o: A = None
        self.t: G = None
        self.txt = txt

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

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

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

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

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

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.r: G = None
        self.s: H = None
        self.v: G = None
        self.q: D = None
        self.o: A = None
        self.t: G = None
        self.txt = txt

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

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

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

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

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