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

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

class C:
    def __init__(self, txt: str):
        self.o: B = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.s: J = None
        self.q: B = None
        self.p: F = None
        self.w: I = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.u: B = None
        self.q: J = None
        self.x: I = None
        self.o: I = None
        self.y: C = None
        self.w: A = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.z: J = None
        self.p: E = None
        self.r: C = None
        self.u: J = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.q: I = None
        self.u: G = None
        self.z: G = None
        self.v: D = None
        self.p: I = None
        self.o: I = None
        self.x: B = None
        self.w: E = None
        self.y: A = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.o: B = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.s: J = None
        self.q: B = None
        self.p: F = None
        self.w: I = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.u: B = None
        self.q: J = None
        self.x: I = None
        self.o: I = None
        self.y: C = None
        self.w: A = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.z: J = None
        self.p: E = None
        self.r: C = None
        self.u: J = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.q: I = None
        self.u: G = None
        self.z: G = None
        self.v: D = None
        self.p: I = None
        self.o: I = None
        self.x: B = None
        self.w: E = None
        self.y: A = None
        self.txt = txt

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

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