class A:
    def __init__(self, txt: str):
        self.w: G = None
        self.t: E = None
        self.s: F = None
        self.y: G = None
        self.v: E = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.y: J = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.s: I = None
        self.x: B = None
        self.z: E = None
        self.p: D = None
        self.r: B = None
        self.u: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.x: G = None
        self.y: G = None
        self.z: A = None
        self.q: H = None
        self.r: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.q: I = None
        self.t: J = None
        self.o: J = None
        self.p: F = None
        self.r: I = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.o: G = None
        self.u: C = None
        self.q: E = None
        self.y: I = None
        self.txt = txt

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

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

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

class J:
    def __init__(self, txt: str):
        self.s: F = None
        self.q: G = None
        self.u: B = None
        self.o: D = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.y: J = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.s: I = None
        self.x: B = None
        self.z: E = None
        self.p: D = None
        self.r: B = None
        self.u: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.x: G = None
        self.y: G = None
        self.z: A = None
        self.q: H = None
        self.r: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.q: I = None
        self.t: J = None
        self.o: J = None
        self.p: F = None
        self.r: I = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.o: G = None
        self.u: C = None
        self.q: E = None
        self.y: I = None
        self.txt = txt

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

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

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

class J:
    def __init__(self, txt: str):
        self.s: F = None
        self.q: G = None
        self.u: B = None
        self.o: D = None
        self.txt = txt

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

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