class A:
    def __init__(self, txt: str):
        self.p: B = None
        self.z: I = None
        self.w: G = None
        self.y: G = None
        self.v: H = None
        self.r: G = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.s: I = None
        self.w: A = None
        self.t: C = None
        self.q: H = None
        self.y: D = None
        self.r: A = None
        self.v: G = None
        self.p: D = None
        self.x: I = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.y: I = None
        self.z: F = None
        self.r: I = None
        self.v: E = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.x: G = None
        self.s: G = None
        self.y: G = None
        self.t: A = None
        self.z: G = None
        self.r: I = None
        self.q: I = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.w: H = None
        self.t: A = None
        self.z: A = None
        self.p: D = None
        self.u: C = None
        self.q: C = None
        self.v: E = None
        self.y: H = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.v: G = None
        self.txt = txt

l = A("l")
f = B("f")
a = C("a")
k = D("k")
m = E("m")
d = F("d")
i = G("i")
e = H("e")
n = I("n")

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

class B:
    def __init__(self, txt: str):
        self.s: I = None
        self.w: A = None
        self.t: C = None
        self.q: H = None
        self.y: D = None
        self.r: A = None
        self.v: G = None
        self.p: D = None
        self.x: I = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.y: I = None
        self.z: F = None
        self.r: I = None
        self.v: E = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.x: G = None
        self.s: G = None
        self.y: G = None
        self.t: A = None
        self.z: G = None
        self.r: I = None
        self.q: I = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.w: H = None
        self.t: A = None
        self.z: A = None
        self.p: D = None
        self.u: C = None
        self.q: C = None
        self.v: E = None
        self.y: H = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.v: G = None
        self.txt = txt

l = A("l")
f = B("f")
a = C("a")
k = D("k")
m = E("m")
d = F("d")
i = G("i")
e = H("e")
n = I("n")

l.p = f
l.z = n
l.w = i
l.y = i
l.r = i
l.v = e
f.s = n
f.x = n
f.w = l
f.r = l
f.t = a
f.q = e
f.y = k
f.p = k
f.v = i
a.y = n
a.r = n
a.z = d
a.v = m
k.o = n
k.s = a
k.v = m
k.t = e
m.x = i
m.s = i
m.y = i
m.z = i
m.t = l
m.r = n
m.q = n
d.w = e
d.y = e
d.t = l
d.z = l
d.p = k
d.u = a
d.q = a
d.v = m
i.s = a
i.q = l
i.y = m
i.v = d
i.o = f
e.w = f
e.r = l
e.x = m
e.s = m
e.o = d
n.v = i
assert f.y.o.v.txt == "i"