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

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

class C:
    def __init__(self, txt: str):
        self.r: G = None
        self.v: E = None
        self.y: I = None
        self.p: G = None
        self.z: H = None
        self.q: E = None
        self.t: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.o: B = None
        self.w: G = None
        self.y: C = None
        self.txt = txt

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

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

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

class H:
    def __init__(self, txt: str):
        self.t: B = None
        self.p: A = None
        self.z: G = None
        self.x: I = None
        self.s: I = None
        self.q: B = None
        self.o: A = None
        self.r: I = None
        self.txt = txt

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

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.r: G = None
        self.v: E = None
        self.y: I = None
        self.p: G = None
        self.z: H = None
        self.q: E = None
        self.t: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.o: B = None
        self.w: G = None
        self.y: C = None
        self.txt = txt

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

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

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

class H:
    def __init__(self, txt: str):
        self.t: B = None
        self.p: A = None
        self.z: G = None
        self.x: I = None
        self.s: I = None
        self.q: B = None
        self.o: A = None
        self.r: I = None
        self.txt = txt

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

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

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

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