class A:
    def __init__(self, txt: str):
        self.s: F = None
        self.q: J = None
        self.t: G = None
        self.y: E = None
        self.w: C = None
        self.z: F = None
        self.v: J = None
        self.o: C = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.s: E = None
        self.z: J = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.w: A = None
        self.y: E = None
        self.s: J = None
        self.t: J = None
        self.v: I = None
        self.r: A = None
        self.z: F = None
        self.o: B = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.o: J = None
        self.p: H = None
        self.x: D = None
        self.w: J = None
        self.v: J = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.v: F = None
        self.q: E = None
        self.s: H = None
        self.z: D = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.o: C = None
        self.q: G = None
        self.s: B = None
        self.z: F = None
        self.w: H = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.o: C = None
        self.y: D = None
        self.p: E = None
        self.w: A = None
        self.r: B = None
        self.x: D = None
        self.v: D = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.s: E = None
        self.z: J = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.w: A = None
        self.y: E = None
        self.s: J = None
        self.t: J = None
        self.v: I = None
        self.r: A = None
        self.z: F = None
        self.o: B = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.o: J = None
        self.p: H = None
        self.x: D = None
        self.w: J = None
        self.v: J = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.v: F = None
        self.q: E = None
        self.s: H = None
        self.z: D = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.o: C = None
        self.q: G = None
        self.s: B = None
        self.z: F = None
        self.w: H = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.o: C = None
        self.y: D = None
        self.p: E = None
        self.w: A = None
        self.r: B = None
        self.x: D = None
        self.v: D = None
        self.txt = txt

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

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