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

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

class C:
    def __init__(self, txt: str):
        self.p: G = None
        self.w: H = None
        self.r: H = None
        self.v: H = None
        self.o: G = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.x: C = None
        self.r: C = None
        self.v: D = None
        self.w: H = None
        self.y: G = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.p: B = None
        self.v: D = None
        self.s: E = None
        self.y: C = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.r: J = None
        self.s: H = None
        self.w: A = None
        self.v: D = None
        self.u: C = None
        self.o: A = None
        self.txt = txt

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.p: G = None
        self.w: H = None
        self.r: H = None
        self.v: H = None
        self.o: G = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.x: C = None
        self.r: C = None
        self.v: D = None
        self.w: H = None
        self.y: G = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.p: B = None
        self.v: D = None
        self.s: E = None
        self.y: C = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.r: J = None
        self.s: H = None
        self.w: A = None
        self.v: D = None
        self.u: C = None
        self.o: A = None
        self.txt = txt

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

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

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