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

class B:
    def __init__(self, txt: str):
        self.p: D = None
        self.s: H = None
        self.r: D = None
        self.v: F = None
        self.y: E = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.v: B = None
        self.y: E = None
        self.txt = txt

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

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

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

class H:
    def __init__(self, txt: str):
        self.t: B = None
        self.p: B = None
        self.v: B = None
        self.u: I = None
        self.x: D = None
        self.w: B = None
        self.o: E = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.p: D = None
        self.s: H = None
        self.r: D = None
        self.v: F = None
        self.y: E = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.v: B = None
        self.y: E = None
        self.txt = txt

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

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

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

class H:
    def __init__(self, txt: str):
        self.t: B = None
        self.p: B = None
        self.v: B = None
        self.u: I = None
        self.x: D = None
        self.w: B = None
        self.o: E = None
        self.txt = txt

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

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

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