class A:
    def __init__(self, txt: str):
        self.v: J = None
        self.r: D = None
        self.s: J = None
        self.o: H = None
        self.y: H = None
        self.w: E = None
        self.p: C = None
        self.x: G = None
        self.u: B = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.x: B = None
        self.w: I = None
        self.u: I = None
        self.z: D = None
        self.o: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.u: B = None
        self.s: E = None
        self.o: I = None
        self.v: H = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.y: H = None
        self.q: B = None
        self.r: B = None
        self.p: H = None
        self.x: A = None
        self.txt = txt

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

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

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

class I:
    def __init__(self, txt: str):
        self.r: E = None
        self.t: B = None
        self.w: F = None
        self.y: B = None
        self.x: H = None
        self.txt = txt

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

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

d.v = i
d.s = i
d.r = f
d.o = b
d.y = b
d.w = l
d.p = a
d.x = n
d.u = g
g.p = d
g.x = a
g.r = a
g.y = i
g.w = i
g.t = i
g.v = m
g.z = c
a.x = g
a.w = m
a.u = m
a.z = f
a.o = d
f.u = g
f.s = l
f.o = m
f.v = b
l.y = b
l.p = b
l.q = g
l.r = g
l.x = d
c.t = n
c.r = b
n.v = c
n.o = c
n.w = i
n.z = g
n.u = g
n.s = l
n.r = m
n.x = m
n.t = b
b.u = n
b.q = n
b.t = n
b.s = c
b.p = c
b.x = i
b.v = i
b.y = g
b.o = f
m.r = l
m.t = g
m.y = g
m.w = c
m.x = b
i.w = f
i.v = a
i.t = a
i.y = a
i.o = n
i.q = g
assert d.y.y.t.txt == "
class A:
    def __init__(self, txt: str):
        self.v: J = None
        self.r: D = None
        self.s: J = None
        self.o: H = None
        self.y: H = None
        self.w: E = None
        self.p: C = None
        self.x: G = None
        self.u: B = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.x: B = None
        self.w: I = None
        self.u: I = None
        self.z: D = None
        self.o: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.u: B = None
        self.s: E = None
        self.o: I = None
        self.v: H = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.y: H = None
        self.q: B = None
        self.r: B = None
        self.p: H = None
        self.x: A = None
        self.txt = txt

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

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

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

class I:
    def __init__(self, txt: str):
        self.r: E = None
        self.t: B = None
        self.w: F = None
        self.y: B = None
        self.x: H = None
        self.txt = txt

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

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

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