class A:
    def __init__(self, txt: str):
        self.z: F = None
        self.r: G = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.v: A = None
        self.u: I = None
        self.x: H = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.p: A = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.o: D = None
        self.p: F = None
        self.s: E = None
        self.y: B = None
        self.w: I = None
        self.r: I = None
        self.t: C = None
        self.txt = txt

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.v: A = None
        self.u: I = None
        self.x: H = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.p: A = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.o: D = None
        self.p: F = None
        self.s: E = None
        self.y: B = None
        self.w: I = None
        self.r: I = None
        self.t: C = None
        self.txt = txt

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

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

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

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