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

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

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

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

class E:
    def __init__(self, txt: str):
        self.y: J = None
        self.w: G = None
        self.p: D = None
        self.t: A = None
        self.x: A = None
        self.v: J = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.r: C = None
        self.o: B = None
        self.z: G = None
        self.q: D = None
        self.x: C = None
        self.t: J = None
        self.v: B = None
        self.u: I = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.q: D = None
        self.r: A = None
        self.y: E = None
        self.u: E = None
        self.z: I = None
        self.p: I = None
        self.v: B = None
        self.t: J = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.z: B = None
        self.x: B = None
        self.q: G = None
        self.r: I = None
        self.u: J = None
        self.txt = txt

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

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

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

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

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

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

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

class E:
    def __init__(self, txt: str):
        self.y: J = None
        self.w: G = None
        self.p: D = None
        self.t: A = None
        self.x: A = None
        self.v: J = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.r: C = None
        self.o: B = None
        self.z: G = None
        self.q: D = None
        self.x: C = None
        self.t: J = None
        self.v: B = None
        self.u: I = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.q: D = None
        self.r: A = None
        self.y: E = None
        self.u: E = None
        self.z: I = None
        self.p: I = None
        self.v: B = None
        self.t: J = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.z: B = None
        self.x: B = None
        self.q: G = None
        self.r: I = None
        self.u: J = None
        self.txt = txt

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

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

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

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