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

class B:
    def __init__(self, txt: str):
        self.o: D = None
        self.v: G = None
        self.s: A = None
        self.z: D = None
        self.q: G = None
        self.w: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.o: A = None
        self.y: E = None
        self.t: A = None
        self.q: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: I = None
        self.y: A = None
        self.t: E = None
        self.x: I = None
        self.s: C = None
        self.q: A = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.w: G = None
        self.v: B = None
        self.t: G = None
        self.u: G = None
        self.r: E = None
        self.y: E = None
        self.o: J = None
        self.p: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: H = None
        self.p: J = None
        self.u: A = None
        self.w: C = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.y: E = None
        self.u: G = None
        self.x: I = None
        self.p: D = None
        self.t: F = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.q: A = None
        self.txt = txt

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

f = A("f")
j = B("j")
h = C("h")
a = D("a")
c = E("c")
n = F("n")
k = G("k")
m = H("m")
d = I("d")
l = J("l")

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

class B:
    def __init__(self, txt: str):
        self.o: D = None
        self.v: G = None
        self.s: A = None
        self.z: D = None
        self.q: G = None
        self.w: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.o: A = None
        self.y: E = None
        self.t: A = None
        self.q: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: I = None
        self.y: A = None
        self.t: E = None
        self.x: I = None
        self.s: C = None
        self.q: A = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.w: G = None
        self.v: B = None
        self.t: G = None
        self.u: G = None
        self.r: E = None
        self.y: E = None
        self.o: J = None
        self.p: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: H = None
        self.p: J = None
        self.u: A = None
        self.w: C = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.y: E = None
        self.u: G = None
        self.x: I = None
        self.p: D = None
        self.t: F = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.q: A = None
        self.txt = txt

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

f = A("f")
j = B("j")
h = C("h")
a = D("a")
c = E("c")
n = F("n")
k = G("k")
m = H("m")
d = I("d")
l = J("l")

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