class A:
    def __init__(self, txt: str):
        self.r: C = None
        self.q: F = None
        self.y: I = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.u: E = None
        self.z: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.y: D = None
        self.t: D = None
        self.p: A = None
        self.w: I = None
        self.r: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.o: G = None
        self.x: G = None
        self.v: B = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.v: H = None
        self.o: D = None
        self.z: D = None
        self.r: D = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.p: C = None
        self.x: B = None
        self.u: G = None
        self.o: C = None
        self.y: D = None
        self.z: E = None
        self.r: E = None
        self.s: F = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.x: E = None
        self.w: B = None
        self.v: F = None
        self.y: G = None
        self.p: D = None
        self.o: B = None
        self.u: C = None
        self.q: E = None
        self.s: H = None
        self.txt = txt

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.u: E = None
        self.z: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.y: D = None
        self.t: D = None
        self.p: A = None
        self.w: I = None
        self.r: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.o: G = None
        self.x: G = None
        self.v: B = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.v: H = None
        self.o: D = None
        self.z: D = None
        self.r: D = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.p: C = None
        self.x: B = None
        self.u: G = None
        self.o: C = None
        self.y: D = None
        self.z: E = None
        self.r: E = None
        self.s: F = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.x: E = None
        self.w: B = None
        self.v: F = None
        self.y: G = None
        self.p: D = None
        self.o: B = None
        self.u: C = None
        self.q: E = None
        self.s: H = None
        self.txt = txt

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

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