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

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

class C:
    def __init__(self, txt: str):
        self.w: E = None
        self.p: A = None
        self.r: G = None
        self.z: E = None
        self.v: A = None
        self.s: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.y: E = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.x: E = None
        self.q: I = None
        self.y: I = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.u: A = None
        self.w: F = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.u: D = None
        self.w: G = None
        self.v: B = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.w: E = None
        self.p: A = None
        self.r: G = None
        self.z: E = None
        self.v: A = None
        self.s: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.y: E = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.x: E = None
        self.q: I = None
        self.y: I = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.u: A = None
        self.w: F = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.u: D = None
        self.w: G = None
        self.v: B = None
        self.txt = txt

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

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