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

class B:
    def __init__(self, txt: str):
        self.s: G = None
        self.p: H = None
        self.v: J = None
        self.x: C = None
        self.o: H = None
        self.z: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.x: G = None
        self.s: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.t: I = None
        self.v: G = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.v: A = None
        self.s: I = None
        self.x: J = None
        self.o: D = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.r: G = None
        self.v: J = None
        self.o: I = None
        self.q: G = None
        self.s: A = None
        self.txt = txt

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.s: G = None
        self.p: H = None
        self.v: J = None
        self.x: C = None
        self.o: H = None
        self.z: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.x: G = None
        self.s: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.t: I = None
        self.v: G = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.v: A = None
        self.s: I = None
        self.x: J = None
        self.o: D = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.r: G = None
        self.v: J = None
        self.o: I = None
        self.q: G = None
        self.s: A = None
        self.txt = txt

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

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

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

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