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

class B:
    def __init__(self, txt: str):
        self.s: G = None
        self.y: E = None
        self.w: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.y: F = None
        self.p: H = None
        self.t: E = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.t: A = None
        self.s: H = None
        self.w: I = None
        self.r: I = None
        self.z: H = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.r: A = None
        self.u: C = None
        self.v: C = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.s: F = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.o: G = None
        self.s: D = None
        self.p: E = None
        self.v: H = None
        self.q: E = None
        self.r: C = None
        self.x: D = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.s: G = None
        self.y: E = None
        self.w: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.y: F = None
        self.p: H = None
        self.t: E = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.t: A = None
        self.s: H = None
        self.w: I = None
        self.r: I = None
        self.z: H = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.r: A = None
        self.u: C = None
        self.v: C = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.s: F = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.o: G = None
        self.s: D = None
        self.p: E = None
        self.v: H = None
        self.q: E = None
        self.r: C = None
        self.x: D = None
        self.txt = txt

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

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