class A:
    def __init__(self, txt: str):
        self.u: G = None
        self.v: H = None
        self.w: F = None
        self.s: D = None
        self.txt = txt

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

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

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

class E:
    def __init__(self, txt: str):
        self.s: C = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.o: J = None
        self.r: E = None
        self.w: D = None
        self.q: D = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.u: B = None
        self.t: G = None
        self.s: J = None
        self.x: H = None
        self.z: G = None
        self.r: C = None
        self.w: G = None
        self.txt = txt

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

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

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

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

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

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

class E:
    def __init__(self, txt: str):
        self.s: C = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.o: J = None
        self.r: E = None
        self.w: D = None
        self.q: D = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.u: B = None
        self.t: G = None
        self.s: J = None
        self.x: H = None
        self.z: G = None
        self.r: C = None
        self.w: G = None
        self.txt = txt

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

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

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