class A:
    def __init__(self, txt: str):
        self.q: I = None
        self.t: J = None
        self.z: G = None
        self.o: H = None
        self.x: I = 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.x: D = None
        self.u: D = None
        self.v: I = None
        self.s: J = None
        self.o: G = None
        self.z: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.s: C = None
        self.p: H = None
        self.t: H = None
        self.o: C = None
        self.y: I = None
        self.q: G = None
        self.v: H = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.w: H = None
        self.s: B = None
        self.p: C = None
        self.x: H = None
        self.u: G = None
        self.q: I = None
        self.v: H = None
        self.o: F = None
        self.z: D = None
        self.y: D = None
        self.txt = txt

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

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

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

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.s: C = None
        self.p: H = None
        self.t: H = None
        self.o: C = None
        self.y: I = None
        self.q: G = None
        self.v: H = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.w: H = None
        self.s: B = None
        self.p: C = None
        self.x: H = None
        self.u: G = None
        self.q: I = None
        self.v: H = None
        self.o: F = None
        self.z: D = None
        self.y: D = None
        self.txt = txt

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

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

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

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

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

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

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