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

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

class C:
    def __init__(self, txt: str):
        self.u: F = None
        self.p: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.s: B = None
        self.q: H = None
        self.x: G = None
        self.t: I = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.t: E = None
        self.w: E = None
        self.u: E = None
        self.r: E = None
        self.z: B = None
        self.o: D = None
        self.x: B = None
        self.q: E = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.v: F = None
        self.txt = txt

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

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

i.z = f
i.q = c
k.v = h
k.x = h
k.o = f
k.s = g
k.t = c
c.u = h
c.p = e
m.s = k
m.q = a
m.x = g
m.t = e
f.w = h
f.x = h
f.t = h
f.r = a
f.z = m
f.y = k
f.u = i
f.p = i
f.s = e
h.t = f
h.w = f
h.u = f
h.r = f
h.q = f
h.z = k
h.x = k
h.o = m
g.t = m
g.v = c
g.o = i
g.w = e
g.z = a
g.q = a
g.p = k
a.v = h
e.x = i
assert a.v.o.s.txt == "
class A:
    def __init__(self, txt: str):
        self.z: E = None
        self.q: C = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.u: F = None
        self.p: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.s: B = None
        self.q: H = None
        self.x: G = None
        self.t: I = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.t: E = None
        self.w: E = None
        self.u: E = None
        self.r: E = None
        self.z: B = None
        self.o: D = None
        self.x: B = None
        self.q: E = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.v: F = None
        self.txt = txt

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

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

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