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

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

class C:
    def __init__(self, txt: str):
        self.u: J = None
        self.t: D = None
        self.s: G = None
        self.w: G = None
        self.p: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.o: B = None
        self.r: J = None
        self.p: E = None
        self.x: J = None
        self.z: I = None
        self.q: E = None
        self.v: B = None
        self.s: G = None
        self.u: J = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.p: D = None
        self.z: A = None
        self.q: A = None
        self.t: C = None
        self.u: H = None
        self.y: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.r: D = None
        self.z: E = None
        self.y: J = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.z: F = None
        self.v: A = None
        self.p: J = None
        self.q: B = None
        self.y: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.s: D = None
        self.r: B = None
        self.o: A = None
        self.w: E = None
        self.p: A = None
        self.txt = txt

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

class J:
    def __init__(self, txt: str):
        self.s: A = None
        self.o: G = None
        self.p: F = None
        self.u: A = None
        self.t: I = None
        self.z: I = None
        self.q: C = None
        self.r: I = None
        self.w: I = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.u: J = None
        self.t: D = None
        self.s: G = None
        self.w: G = None
        self.p: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.o: B = None
        self.r: J = None
        self.p: E = None
        self.x: J = None
        self.z: I = None
        self.q: E = None
        self.v: B = None
        self.s: G = None
        self.u: J = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.p: D = None
        self.z: A = None
        self.q: A = None
        self.t: C = None
        self.u: H = None
        self.y: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.r: D = None
        self.z: E = None
        self.y: J = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.z: F = None
        self.v: A = None
        self.p: J = None
        self.q: B = None
        self.y: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.s: D = None
        self.r: B = None
        self.o: A = None
        self.w: E = None
        self.p: A = None
        self.txt = txt

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

class J:
    def __init__(self, txt: str):
        self.s: A = None
        self.o: G = None
        self.p: F = None
        self.u: A = None
        self.t: I = None
        self.z: I = None
        self.q: C = None
        self.r: I = None
        self.w: I = None
        self.txt = txt

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

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