### connected sum of knots

Hi! I was trying to recursively construct connected sums of knots, but I seem to run in to some problems when connect summing a knot to itself more than two times:

B = BraidGroup(2)

trefoil = Knot(B([1,1,1]))

K = trefoil.connected_sum(trefoil)

L = K.connected_sum(trefoil)

This does not work:

```
ValueError Traceback (most recent call last)
ipython-input-1-7b977cf99468 in module()
2 trefoil = Knot(B([Integer(1),Integer(1),Integer(1)]))
3 K = trefoil.connected_sum(trefoil)
--> 4 L = K.connected_sum(trefoil)
/home/sc_serv/sage/local/lib/python2.7/site-packages/sage/knots/knot.pyc in connected_sum(self, other)
294 return Knot(B(list(b1.Tietze())
295 + [(abs(i) + b2s) * Integer(i).sign() for i in b2.Tietze()]
--> 296 + [b1s]))
297
/home/sc_serv/sage/local/lib/python2.7/site-packages/sage/knots/knot.pyc in __init__(self, data, check)
104 if check:
105 if self.number_of_components() != 1:
--> 106 raise ValueError("the input has more than 1 connected component")
107
108 def __repr__(self):
ValueError: the input has more than 1 connected component
```

Am I doing something wrong here?
Thanks in advance!