class A:
    def __init__(self, txt: str):
        self.y: D = None
        self.s: D = None
        self.u: I = None
        self.v: J = None
        self.q: F = None
        self.o: H = None
        self.r: F = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.x: A = None
        self.p: D = None
        self.o: J = None
        self.t: B = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.y: H = None
        self.o: F = None
        self.v: C = None
        self.r: F = None
        self.s: H = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.p: I = None
        self.t: G = None
        self.r: G = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.x: J = None
        self.txt = txt

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

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

class J:
    def __init__(self, txt: str):
        self.t: F = None
        self.z: E = None
        self.u: A = None
        self.q: F = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.x: A = None
        self.p: D = None
        self.o: J = None
        self.t: B = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.y: H = None
        self.o: F = None
        self.v: C = None
        self.r: F = None
        self.s: H = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.p: I = None
        self.t: G = None
        self.r: G = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.x: J = None
        self.txt = txt

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

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

class J:
    def __init__(self, txt: str):
        self.t: F = None
        self.z: E = None
        self.u: A = None
        self.q: F = None
        self.txt = txt

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

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