class A:
    def __init__(self, txt: str):
        self.v: G = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.z: I = None
        self.u: F = None
        self.v: G = None
        self.w: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.x: B = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.s: I = None
        self.w: A = None
        self.r: C = None
        self.u: D = None
        self.o: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.o: C = None
        self.w: D = None
        self.r: C = None
        self.s: C = None
        self.x: A = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.o: C = None
        self.r: C = None
        self.z: B = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.z: I = None
        self.u: F = None
        self.v: G = None
        self.w: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.x: B = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.s: I = None
        self.w: A = None
        self.r: C = None
        self.u: D = None
        self.o: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.o: C = None
        self.w: D = None
        self.r: C = None
        self.s: C = None
        self.x: A = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.o: C = None
        self.r: C = None
        self.z: B = None
        self.txt = txt

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

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