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

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

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

class D:
    def __init__(self, txt: str):
        self.r: G = None
        self.u: B = None
        self.q: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.q: I = None
        self.x: G = None
        self.s: I = None
        self.u: C = None
        self.r: F = None
        self.t: J = None
        self.p: I = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.u: H = None
        self.o: B = None
        self.v: B = None
        self.y: J = None
        self.txt = txt

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

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

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

class J:
    def __init__(self, txt: str):
        self.z: C = None
        self.u: A = None
        self.o: C = None
        self.y: G = None
        self.r: D = None
        self.p: E = None
        self.x: G = None
        self.w: C = None
        self.t: F = None
        self.txt = txt

i = A("i")
l = B("l")
a = C("a")
m = D("m")
k = E("k")
f = F("f")
d = G("d")
g = H("g")
h = I("h")
b = J("b")

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

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

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

class D:
    def __init__(self, txt: str):
        self.r: G = None
        self.u: B = None
        self.q: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.q: I = None
        self.x: G = None
        self.s: I = None
        self.u: C = None
        self.r: F = None
        self.t: J = None
        self.p: I = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.u: H = None
        self.o: B = None
        self.v: B = None
        self.y: J = None
        self.txt = txt

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

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

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

class J:
    def __init__(self, txt: str):
        self.z: C = None
        self.u: A = None
        self.o: C = None
        self.y: G = None
        self.r: D = None
        self.p: E = None
        self.x: G = None
        self.w: C = None
        self.t: F = None
        self.txt = txt

i = A("i")
l = B("l")
a = C("a")
m = D("m")
k = E("k")
f = F("f")
d = G("d")
g = H("g")
h = I("h")
b = J("b")

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