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

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

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

class D:
    def __init__(self, txt: str):
        self.s: E = None
        self.w: B = None
        self.y: C = None
        self.p: G = None
        self.z: J = None
        self.q: F = None
        self.o: I = None
        self.u: E = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: A = None
        self.p: G = None
        self.z: C = None
        self.s: B = None
        self.t: J = None
        self.u: J = None
        self.v: I = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.t: C = None
        self.r: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.r: J = None
        self.s: D = None
        self.y: C = None
        self.p: H = None
        self.o: B = None
        self.txt = txt

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

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

class J:
    def __init__(self, txt: str):
        self.v: I = None
        self.p: F = None
        self.y: G = None
        self.z: I = None
        self.q: G = None
        self.w: I = None
        self.r: C = None
        self.o: I = None
        self.txt = txt

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.s: E = None
        self.w: B = None
        self.y: C = None
        self.p: G = None
        self.z: J = None
        self.q: F = None
        self.o: I = None
        self.u: E = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: A = None
        self.p: G = None
        self.z: C = None
        self.s: B = None
        self.t: J = None
        self.u: J = None
        self.v: I = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.t: C = None
        self.r: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.r: J = None
        self.s: D = None
        self.y: C = None
        self.p: H = None
        self.o: B = None
        self.txt = txt

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

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

class J:
    def __init__(self, txt: str):
        self.v: I = None
        self.p: F = None
        self.y: G = None
        self.z: I = None
        self.q: G = None
        self.w: I = None
        self.r: C = None
        self.o: I = None
        self.txt = txt

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

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