class A:
    def __init__(self, txt: str):
        self.s: F = None
        self.o: F = None
        self.z: E = None
        self.q: E = None
        self.u: E = None
        self.w: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.z: I = None
        self.t: F = None
        self.y: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.y: A = None
        self.u: H = None
        self.x: I = None
        self.s: H = None
        self.z: H = None
        self.w: I = None
        self.o: F = None
        self.p: A = None
        self.txt = txt

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

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

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

class G:
    def __init__(self, txt: str):
        self.r: H = None
        self.x: D = None
        self.y: A = None
        self.z: F = None
        self.o: C = None
        self.s: H = None
        self.q: H = None
        self.t: B = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.w: F = None
        self.r: C = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.p: D = None
        self.s: C = None
        self.r: B = None
        self.y: A = None
        self.z: D = None
        self.t: E = None
        self.v: B = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.z: I = None
        self.t: F = None
        self.y: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.y: A = None
        self.u: H = None
        self.x: I = None
        self.s: H = None
        self.z: H = None
        self.w: I = None
        self.o: F = None
        self.p: A = None
        self.txt = txt

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

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

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

class G:
    def __init__(self, txt: str):
        self.r: H = None
        self.x: D = None
        self.y: A = None
        self.z: F = None
        self.o: C = None
        self.s: H = None
        self.q: H = None
        self.t: B = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.w: F = None
        self.r: C = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.p: D = None
        self.s: C = None
        self.r: B = None
        self.y: A = None
        self.z: D = None
        self.t: E = None
        self.v: B = None
        self.txt = txt

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

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