class A:
    def __init__(self, txt: str):
        self.w: F = None
        self.o: I = None
        self.q: G = None
        self.y: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.s: G = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.r: F = None
        self.u: I = None
        self.s: B = None
        self.t: G = None
        self.txt = txt

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

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

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

class I:
    def __init__(self, txt: str):
        self.y: H = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.s: G = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.r: F = None
        self.u: I = None
        self.s: B = None
        self.t: G = None
        self.txt = txt

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

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

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

class I:
    def __init__(self, txt: str):
        self.y: H = None
        self.txt = txt

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

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

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