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

class B:
    def __init__(self, txt: str):
        self.q: F = None
        self.r: A = None
        self.u: A = None
        self.y: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.t: B = None
        self.o: C = None
        self.r: F = None
        self.w: E = None
        self.v: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.r: A = None
        self.u: F = None
        self.q: C = None
        self.y: C = None
        self.z: D = None
        self.t: H = None
        self.x: C = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.w: H = None
        self.r: E = None
        self.x: H = None
        self.q: A = None
        self.p: B = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.z: H = None
        self.s: F = None
        self.o: C = None
        self.t: B = None
        self.x: H = None
        self.r: A = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.q: F = None
        self.r: A = None
        self.u: A = None
        self.y: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.t: B = None
        self.o: C = None
        self.r: F = None
        self.w: E = None
        self.v: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.r: A = None
        self.u: F = None
        self.q: C = None
        self.y: C = None
        self.z: D = None
        self.t: H = None
        self.x: C = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.w: H = None
        self.r: E = None
        self.x: H = None
        self.q: A = None
        self.p: B = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.z: H = None
        self.s: F = None
        self.o: C = None
        self.t: B = None
        self.x: H = None
        self.r: A = None
        self.txt = txt

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

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