class A:
    def __init__(self, txt: str):
        self.v: G = None
        self.p: J = None
        self.x: H = None
        self.z: C = None
        self.y: D = None
        self.w: E = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.y: I = None
        self.r: J = None
        self.s: A = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.z: H = None
        self.y: A = None
        self.x: J = None
        self.r: I = None
        self.t: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.s: D = None
        self.u: E = None
        self.p: I = None
        self.o: D = None
        self.r: H = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.v: B = None
        self.t: F = None
        self.s: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.u: D = None
        self.p: G = None
        self.v: D = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.x: B = None
        self.v: C = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.y: I = None
        self.r: J = None
        self.s: A = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.z: H = None
        self.y: A = None
        self.x: J = None
        self.r: I = None
        self.t: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.s: D = None
        self.u: E = None
        self.p: I = None
        self.o: D = None
        self.r: H = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.v: B = None
        self.t: F = None
        self.s: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.u: D = None
        self.p: G = None
        self.v: D = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.x: B = None
        self.v: C = None
        self.txt = txt

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

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

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