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

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

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

class D:
    def __init__(self, txt: str):
        self.t: A = None
        self.y: C = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.r: B = None
        self.s: G = None
        self.w: A = None
        self.z: A = None
        self.u: A = None
        self.p: J = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.t: H = None
        self.q: B = None
        self.z: B = None
        self.p: A = None
        self.y: I = None
        self.w: B = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.z: B = None
        self.o: H = None
        self.txt = txt

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

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.t: A = None
        self.y: C = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.r: B = None
        self.s: G = None
        self.w: A = None
        self.z: A = None
        self.u: A = None
        self.p: J = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.t: H = None
        self.q: B = None
        self.z: B = None
        self.p: A = None
        self.y: I = None
        self.w: B = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.z: B = None
        self.o: H = None
        self.txt = txt

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

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

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