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

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

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

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

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

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

class G:
    def __init__(self, txt: str):
        self.o: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.s: C = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.u: G = None
        self.q: C = None
        self.y: F = None
        self.r: E = None
        self.x: H = None
        self.o: F = None
        self.s: H = None
        self.w: D = None
        self.txt = txt

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

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

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

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

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

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

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

class G:
    def __init__(self, txt: str):
        self.o: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.s: C = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.u: G = None
        self.q: C = None
        self.y: F = None
        self.r: E = None
        self.x: H = None
        self.o: F = None
        self.s: H = None
        self.w: D = None
        self.txt = txt

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

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