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

class B:
    def __init__(self, txt: str):
        self.t: C = None
        self.y: C = None
        self.s: C = None
        self.z: H = None
        self.x: G = None
        self.u: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.p: H = None
        self.t: D = None
        self.q: H = None
        self.r: B = None
        self.z: A = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.s: G = None
        self.w: F = None
        self.z: H = None
        self.q: C = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.o: I = None
        self.v: F = None
        self.t: B = None
        self.txt = txt

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.t: C = None
        self.y: C = None
        self.s: C = None
        self.z: H = None
        self.x: G = None
        self.u: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.p: H = None
        self.t: D = None
        self.q: H = None
        self.r: B = None
        self.z: A = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.s: G = None
        self.w: F = None
        self.z: H = None
        self.q: C = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.o: I = None
        self.v: F = None
        self.t: B = None
        self.txt = txt

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

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

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

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