class A:
    def __init__(self, txt: str):
        self.y: H = None
        self.p: E = None
        self.x: C = None
        self.o: I = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.r: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.x: I = None
        self.t: H = None
        self.p: E = None
        self.z: E = None
        self.txt = txt

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

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

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

class H:
    def __init__(self, txt: str):
        self.s: I = None
        self.u: I = None
        self.y: D = None
        self.t: F = None
        self.p: F = None
        self.q: E = None
        self.txt = txt

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.r: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.x: I = None
        self.t: H = None
        self.p: E = None
        self.z: E = None
        self.txt = txt

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

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

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

class H:
    def __init__(self, txt: str):
        self.s: I = None
        self.u: I = None
        self.y: D = None
        self.t: F = None
        self.p: F = None
        self.q: E = None
        self.txt = txt

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

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

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