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

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

class C:
    def __init__(self, txt: str):
        self.y: A = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.q: I = None
        self.txt = txt

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

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

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

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.y: A = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.q: I = None
        self.txt = txt

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

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

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

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

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

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