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

class B:
    def __init__(self, txt: str):
        self.r: C = None
        self.u: F = None
        self.y: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.v: D = None
        self.r: J = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.r: B = None
        self.v: I = None
        self.y: I = None
        self.z: H = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.z: C = None
        self.y: J = None
        self.s: I = None
        self.r: B = None
        self.t: A = None
        self.u: G = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.w: D = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.u: I = None
        self.q: E = None
        self.z: E = None
        self.p: G = None
        self.x: J = None
        self.y: I = None
        self.s: B = None
        self.t: F = None
        self.w: C = None
        self.txt = txt

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

class J:
    def __init__(self, txt: str):
        self.q: A = None
        self.u: D = None
        self.w: F = None
        self.x: G = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.r: C = None
        self.u: F = None
        self.y: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.v: D = None
        self.r: J = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.r: B = None
        self.v: I = None
        self.y: I = None
        self.z: H = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.z: C = None
        self.y: J = None
        self.s: I = None
        self.r: B = None
        self.t: A = None
        self.u: G = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.w: D = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.u: I = None
        self.q: E = None
        self.z: E = None
        self.p: G = None
        self.x: J = None
        self.y: I = None
        self.s: B = None
        self.t: F = None
        self.w: C = None
        self.txt = txt

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

class J:
    def __init__(self, txt: str):
        self.q: A = None
        self.u: D = None
        self.w: F = None
        self.x: G = None
        self.txt = txt

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

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