class A:
    def __init__(self, txt: str):
        self.v: F = None
        self.o: G = None
        self.y: E = None
        self.r: I = None
        self.w: E = None
        self.t: H = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.z: D = None
        self.u: E = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.u: C = None
        self.q: I = None
        self.r: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: C = None
        self.y: B = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.z: F = None
        self.r: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.v: C = None
        self.r: I = None
        self.q: C = None
        self.x: C = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.y: E = None
        self.v: F = None
        self.o: A = None
        self.txt = txt

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

n.v = a
n.o = i
n.y = k
n.w = k
n.r = d
n.t = e
c.z = b
c.u = k
j.s = d
j.v = d
j.w = n
b.u = j
b.r = j
b.q = d
k.o = j
k.y = c
a.u = c
a.z = c
i.z = a
i.r = k
e.v = j
e.q = j
e.x = j
e.r = d
d.y = k
d.v = a
d.o = n
assert a.u.z.q.v.z.txt == "
class A:
    def __init__(self, txt: str):
        self.v: F = None
        self.o: G = None
        self.y: E = None
        self.r: I = None
        self.w: E = None
        self.t: H = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.z: D = None
        self.u: E = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.u: C = None
        self.q: I = None
        self.r: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: C = None
        self.y: B = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.z: F = None
        self.r: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.v: C = None
        self.r: I = None
        self.q: C = None
        self.x: C = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.y: E = None
        self.v: F = None
        self.o: A = None
        self.txt = txt

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

n.v = a
n.o = i
n.y = k
n.w = k
n.r = d
n.t = e
c.z = b
c.u = k
j.s = d
j.v = d
j.w = n
b.u = j
b.r = j
b.q = d
k.o = j
k.y = c
a.u = c
a.z = c
i.z = a
i.r = k
e.v = j
e.q = j
e.x = j
e.r = d
d.y = k
d.v = a
d.o = n
assert a.u.z.q.v.z.txt == "c"