class A:
    def __init__(self, txt: str):
        self.u: D = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.z: B = None
        self.r: I = None
        self.t: F = None
        self.o: F = None
        self.x: E = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.y: F = None
        self.w: F = None
        self.x: J = None
        self.o: H = None
        self.u: B = None
        self.r: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.x: B = None
        self.z: C = None
        self.t: D = None
        self.txt = txt

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

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

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

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

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.z: B = None
        self.r: I = None
        self.t: F = None
        self.o: F = None
        self.x: E = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.y: F = None
        self.w: F = None
        self.x: J = None
        self.o: H = None
        self.u: B = None
        self.r: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.x: B = None
        self.z: C = None
        self.t: D = None
        self.txt = txt

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

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

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

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

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

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