class A:
    def __init__(self, txt: str):
        self.t: I = None
        self.o: I = None
        self.p: F = None
        self.u: G = None
        self.s: C = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.u: E = None
        self.z: H = None
        self.r: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.s: I = None
        self.v: E = None
        self.txt = txt

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

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

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

class G:
    def __init__(self, txt: str):
        self.u: D = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.v: E = None
        self.o: A = None
        self.y: D = None
        self.t: A = None
        self.x: E = None
        self.q: A = None
        self.r: F = None
        self.s: D = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.y: F = None
        self.z: H = None
        self.q: B = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.u: E = None
        self.z: H = None
        self.r: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.s: I = None
        self.v: E = None
        self.txt = txt

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

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

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

class G:
    def __init__(self, txt: str):
        self.u: D = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.v: E = None
        self.o: A = None
        self.y: D = None
        self.t: A = None
        self.x: E = None
        self.q: A = None
        self.r: F = None
        self.s: D = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.y: F = None
        self.z: H = None
        self.q: B = None
        self.txt = txt

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

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