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

class B:
    def __init__(self, txt: str):
        self.s: C = None
        self.x: C = None
        self.r: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.w: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.x: I = None
        self.w: I = None
        self.q: G = None
        self.r: A = None
        self.t: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.t: C = None
        self.x: C = None
        self.z: C = None
        self.r: C = None
        self.w: G = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.u: H = None
        self.x: A = None
        self.r: I = None
        self.w: D = None
        self.q: H = None
        self.z: I = None
        self.o: A = None
        self.t: H = None
        self.s: H = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.r: F = None
        self.u: D = None
        self.s: G = None
        self.p: F = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.s: C = None
        self.x: C = None
        self.r: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.w: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.x: I = None
        self.w: I = None
        self.q: G = None
        self.r: A = None
        self.t: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.t: C = None
        self.x: C = None
        self.z: C = None
        self.r: C = None
        self.w: G = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.u: H = None
        self.x: A = None
        self.r: I = None
        self.w: D = None
        self.q: H = None
        self.z: I = None
        self.o: A = None
        self.t: H = None
        self.s: H = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.r: F = None
        self.u: D = None
        self.s: G = None
        self.p: F = None
        self.txt = txt

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

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

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