class A:
    def __init__(self, txt: str):
        self.t: E = None
        self.r: I = None
        self.s: H = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.z: C = None
        self.u: A = None
        self.s: E = None
        self.p: I = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.s: G = None
        self.y: H = None
        self.v: I = None
        self.o: E = None
        self.r: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.q: H = None
        self.x: F = None
        self.z: F = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: B = None
        self.s: H = None
        self.t: H = None
        self.w: B = None
        self.v: A = None
        self.z: A = None
        self.u: A = None
        self.txt = txt

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

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

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

class I:
    def __init__(self, txt: str):
        self.u: H = None
        self.o: G = None
        self.y: H = None
        self.q: H = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.z: C = None
        self.u: A = None
        self.s: E = None
        self.p: I = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.s: G = None
        self.y: H = None
        self.v: I = None
        self.o: E = None
        self.r: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.q: H = None
        self.x: F = None
        self.z: F = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: B = None
        self.s: H = None
        self.t: H = None
        self.w: B = None
        self.v: A = None
        self.z: A = None
        self.u: A = None
        self.txt = txt

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

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

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

class I:
    def __init__(self, txt: str):
        self.u: H = None
        self.o: G = None
        self.y: H = None
        self.q: H = None
        self.txt = txt

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

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