class A:
    def __init__(self, txt: str):
        self.u: F = None
        self.z: J = None
        self.p: F = None
        self.w: D = None
        self.s: F = None
        self.x: F = None
        self.t: I = None
        self.o: F = None
        self.q: C = None
        self.v: C = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.t: I = None
        self.u: G = None
        self.r: D = None
        self.w: D = None
        self.s: G = None
        self.z: I = None
        self.o: H = None
        self.q: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.p: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.x: I = None
        self.s: B = None
        self.r: C = None
        self.q: A = None
        self.w: F = None
        self.z: A = None
        self.y: B = None
        self.p: B = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.t: I = None
        self.v: E = None
        self.z: A = None
        self.s: D = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.s: D = None
        self.o: J = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.v: A = None
        self.u: F = None
        self.x: A = None
        self.r: C = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.t: I = None
        self.u: G = None
        self.r: D = None
        self.w: D = None
        self.s: G = None
        self.z: I = None
        self.o: H = None
        self.q: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.p: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.x: I = None
        self.s: B = None
        self.r: C = None
        self.q: A = None
        self.w: F = None
        self.z: A = None
        self.y: B = None
        self.p: B = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.t: I = None
        self.v: E = None
        self.z: A = None
        self.s: D = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.s: D = None
        self.o: J = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.v: A = None
        self.u: F = None
        self.x: A = None
        self.r: C = None
        self.txt = txt

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

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