class A:
    def __init__(self, txt: str):
        self.y: H = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.v: C = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.w: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.z: C = None
        self.q: G = None
        self.x: D = None
        self.t: A = None
        self.r: I = None
        self.o: G = None
        self.u: I = None
        self.p: H = None
        self.s: D = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.u: B = None
        self.y: B = None
        self.z: I = None
        self.t: I = None
        self.r: A = None
        self.o: D = None
        self.p: E = None
        self.x: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.v: B = None
        self.x: A = None
        self.s: D = None
        self.y: D = None
        self.q: A = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.y: C = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.v: C = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.w: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.z: C = None
        self.q: G = None
        self.x: D = None
        self.t: A = None
        self.r: I = None
        self.o: G = None
        self.u: I = None
        self.p: H = None
        self.s: D = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.u: B = None
        self.y: B = None
        self.z: I = None
        self.t: I = None
        self.r: A = None
        self.o: D = None
        self.p: E = None
        self.x: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.v: B = None
        self.x: A = None
        self.s: D = None
        self.y: D = None
        self.q: A = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.y: C = None
        self.txt = txt

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

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

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