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

class B:
    def __init__(self, txt: str):
        self.z: H = None
        self.u: G = None
        self.y: E = None
        self.r: I = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.w: A = None
        self.u: E = None
        self.s: A = None
        self.x: G = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.r: A = None
        self.s: E = None
        self.o: A = None
        self.t: A = None
        self.w: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.z: E = None
        self.q: E = None
        self.u: A = None
        self.s: D = None
        self.w: E = None
        self.v: B = None
        self.p: A = None
        self.o: B = None
        self.y: I = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.o: G = None
        self.v: C = None
        self.z: F = None
        self.w: D = None
        self.y: F = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.z: H = None
        self.u: G = None
        self.y: E = None
        self.r: I = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.w: A = None
        self.u: E = None
        self.s: A = None
        self.x: G = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.r: A = None
        self.s: E = None
        self.o: A = None
        self.t: A = None
        self.w: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.z: E = None
        self.q: E = None
        self.u: A = None
        self.s: D = None
        self.w: E = None
        self.v: B = None
        self.p: A = None
        self.o: B = None
        self.y: I = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.o: G = None
        self.v: C = None
        self.z: F = None
        self.w: D = None
        self.y: F = None
        self.txt = txt

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

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

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