class A:
    def __init__(self, txt: str):
        self.o: I = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.p: E = None
        self.v: F = None
        self.u: E = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.q: C = None
        self.w: E = None
        self.o: E = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.w: C = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.p: B = None
        self.t: G = None
        self.txt = txt

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

class J:
    def __init__(self, txt: str):
        self.r: H = None
        self.w: F = None
        self.v: G = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.p: E = None
        self.v: F = None
        self.u: E = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.q: C = None
        self.w: E = None
        self.o: E = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.w: C = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.p: B = None
        self.t: G = None
        self.txt = txt

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

class J:
    def __init__(self, txt: str):
        self.r: H = None
        self.w: F = None
        self.v: G = None
        self.txt = txt

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

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