class A:
    def __init__(self, txt: str):
        self.r: D = None
        self.x: B = None
        self.s: F = None
        self.w: C = None
        self.u: B = None
        self.v: D = None
        self.q: F = None
        self.y: B = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.o: H = None
        self.x: F = None
        self.y: C = None
        self.s: C = None
        self.u: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.x: H = None
        self.v: H = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.x: I = None
        self.v: F = None
        self.z: E = None
        self.q: F = None
        self.s: C = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.u: C = None
        self.r: G = None
        self.o: C = None
        self.y: B = None
        self.txt = txt

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.o: H = None
        self.x: F = None
        self.y: C = None
        self.s: C = None
        self.u: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.x: H = None
        self.v: H = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.x: I = None
        self.v: F = None
        self.z: E = None
        self.q: F = None
        self.s: C = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.u: C = None
        self.r: G = None
        self.o: C = None
        self.y: B = None
        self.txt = txt

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

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