class A:
    def __init__(self, txt: str):
        self.v: E = None
        self.t: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.w: E = None
        self.y: F = None
        self.u: D = None
        self.o: D = None
        self.r: G = None
        self.t: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.y: I = None
        self.p: J = None
        self.w: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.o: B = None
        self.y: H = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.p: B = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.r: H = None
        self.s: A = None
        self.y: F = None
        self.t: H = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.x: B = None
        self.w: F = None
        self.p: D = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.s: F = None
        self.w: E = None
        self.r: F = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.x: E = None
        self.p: B = None
        self.w: I = None
        self.y: H = None
        self.txt = txt

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

i.v = b
i.t = h
n.w = b
n.t = b
n.y = h
n.u = k
n.o = k
n.r = e
c.y = a
c.w = a
c.p = l
k.o = n
k.y = f
b.p = n
h.u = a
h.r = f
e.r = f
e.t = f
e.s = i
e.y = h
f.x = n
f.w = h
f.p = k
a.s = h
a.r = h
a.w = b
l.x = b
l.p = n
l.w = a
l.y = f
assert i.t.u.w.p.r.s.txt == "
class A:
    def __init__(self, txt: str):
        self.v: E = None
        self.t: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.w: E = None
        self.y: F = None
        self.u: D = None
        self.o: D = None
        self.r: G = None
        self.t: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.y: I = None
        self.p: J = None
        self.w: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.o: B = None
        self.y: H = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.p: B = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.r: H = None
        self.s: A = None
        self.y: F = None
        self.t: H = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.x: B = None
        self.w: F = None
        self.p: D = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.s: F = None
        self.w: E = None
        self.r: F = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.x: E = None
        self.p: B = None
        self.w: I = None
        self.y: H = None
        self.txt = txt

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

i.v = b
i.t = h
n.w = b
n.t = b
n.y = h
n.u = k
n.o = k
n.r = e
c.y = a
c.w = a
c.p = l
k.o = n
k.y = f
b.p = n
h.u = a
h.r = f
e.r = f
e.t = f
e.s = i
e.y = h
f.x = n
f.w = h
f.p = k
a.s = h
a.r = h
a.w = b
l.x = b
l.p = n
l.w = a
l.y = f
assert i.t.u.w.p.r.s.txt == "i"