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

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

class C:
    def __init__(self, txt: str):
        self.w: J = None
        self.q: J = None
        self.t: F = None
        self.x: J = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.y: A = None
        self.v: A = None
        self.r: J = None
        self.s: E = None
        self.o: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.x: C = None
        self.t: G = None
        self.o: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.p: J = None
        self.y: D = None
        self.r: C = None
        self.u: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.v: A = None
        self.t: F = None
        self.o: H = None
        self.u: B = None
        self.y: H = None
        self.w: I = None
        self.q: E = None
        self.s: H = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.r: A = None
        self.txt = txt

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

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.w: J = None
        self.q: J = None
        self.t: F = None
        self.x: J = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.y: A = None
        self.v: A = None
        self.r: J = None
        self.s: E = None
        self.o: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.x: C = None
        self.t: G = None
        self.o: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.p: J = None
        self.y: D = None
        self.r: C = None
        self.u: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.v: A = None
        self.t: F = None
        self.o: H = None
        self.u: B = None
        self.y: H = None
        self.w: I = None
        self.q: E = None
        self.s: H = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.r: A = None
        self.txt = txt

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

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

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

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