class A:
    def __init__(self, txt: str):
        self.q: F = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.t: B = None
        self.y: I = None
        self.o: G = None
        self.z: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.x: B = None
        self.q: G = None
        self.w: C = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.y: D = None
        self.x: A = None
        self.r: I = None
        self.v: C = None
        self.t: C = None
        self.txt = txt

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

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

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.t: B = None
        self.y: I = None
        self.o: G = None
        self.z: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.x: B = None
        self.q: G = None
        self.w: C = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.y: D = None
        self.x: A = None
        self.r: I = None
        self.v: C = None
        self.t: C = None
        self.txt = txt

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

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

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

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