class A:
    def __init__(self, txt: str):
        self.v: C = None
        self.y: E = None
        self.s: E = None
        self.z: J = None
        self.p: C = None
        self.q: J = None
        self.w: B = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.w: J = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.q: E = None
        self.r: A = None
        self.u: A = None
        self.s: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.x: I = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.y: G = None
        self.x: H = None
        self.z: D = None
        self.q: J = None
        self.o: J = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.r: C = None
        self.w: H = None
        self.t: F = None
        self.p: A = None
        self.s: F = None
        self.z: E = None
        self.v: I = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.x: A = None
        self.w: C = None
        self.q: G = None
        self.z: B = None
        self.t: B = None
        self.v: G = None
        self.s: B = None
        self.o: B = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.w: J = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.q: E = None
        self.r: A = None
        self.u: A = None
        self.s: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.x: I = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.y: G = None
        self.x: H = None
        self.z: D = None
        self.q: J = None
        self.o: J = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.r: C = None
        self.w: H = None
        self.t: F = None
        self.p: A = None
        self.s: F = None
        self.z: E = None
        self.v: I = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.x: A = None
        self.w: C = None
        self.q: G = None
        self.z: B = None
        self.t: B = None
        self.v: G = None
        self.s: B = None
        self.o: B = None
        self.txt = txt

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

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

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