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

class B:
    def __init__(self, txt: str):
        self.q: I = None
        self.w: F = None
        self.v: C = None
        self.o: A = None
        self.x: C = None
        self.s: C = None
        self.p: C = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.w: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.y: H = None
        self.x: B = None
        self.t: E = None
        self.w: C = None
        self.r: B = None
        self.u: E = None
        self.s: B = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.o: A = None
        self.s: D = None
        self.x: A = None
        self.w: A = None
        self.y: G = None
        self.q: G = None
        self.v: I = None
        self.z: C = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.u: B = None
        self.p: D = None
        self.y: E = None
        self.w: D = None
        self.v: I = None
        self.r: F = None
        self.t: B = None
        self.s: B = None
        self.o: C = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.o: I = None
        self.s: D = None
        self.u: F = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.q: I = None
        self.w: F = None
        self.v: C = None
        self.o: A = None
        self.x: C = None
        self.s: C = None
        self.p: C = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.w: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.y: H = None
        self.x: B = None
        self.t: E = None
        self.w: C = None
        self.r: B = None
        self.u: E = None
        self.s: B = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.o: A = None
        self.s: D = None
        self.x: A = None
        self.w: A = None
        self.y: G = None
        self.q: G = None
        self.v: I = None
        self.z: C = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.u: B = None
        self.p: D = None
        self.y: E = None
        self.w: D = None
        self.v: I = None
        self.r: F = None
        self.t: B = None
        self.s: B = None
        self.o: C = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.o: I = None
        self.s: D = None
        self.u: F = None
        self.txt = txt

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

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

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