class A:
    def __init__(self, txt: str):
        self.v: F = None
        self.r: E = None
        self.t: E = None
        self.w: I = None
        self.u: C = None
        self.p: C = None
        self.x: C = None
        self.o: F = None
        self.s: E = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.s: C = None
        self.q: F = None
        self.y: I = None
        self.z: I = None
        self.t: G = None
        self.v: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: F = None
        self.txt = txt

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

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

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

class G:
    def __init__(self, txt: str):
        self.s: B = None
        self.v: A = None
        self.o: C = None
        self.t: H = None
        self.u: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.q: G = None
        self.x: I = None
        self.y: B = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.y: C = None
        self.u: G = None
        self.z: A = None
        self.r: C = None
        self.o: C = None
        self.s: B = None
        self.t: B = None
        self.p: C = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.s: C = None
        self.q: F = None
        self.y: I = None
        self.z: I = None
        self.t: G = None
        self.v: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: F = None
        self.txt = txt

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

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

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

class G:
    def __init__(self, txt: str):
        self.s: B = None
        self.v: A = None
        self.o: C = None
        self.t: H = None
        self.u: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.q: G = None
        self.x: I = None
        self.y: B = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.y: C = None
        self.u: G = None
        self.z: A = None
        self.r: C = None
        self.o: C = None
        self.s: B = None
        self.t: B = None
        self.p: C = None
        self.txt = txt

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

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