def perm(l):
        # Compute the list of all permutations of l
    if len(l) <= 1:
		return [l]
    r = []
    for i in range(len(l)): 
             s = l[:i] + l[i+1:]
             p = perm(s)
             for x in p:
		r.append(l[i:i+1] + x)
    return r