Cat problem (1-liner)

(lambda n:(lambda p,g,b,u:(list(__import__('itertools').takewhile(lambda x:(False,)*n not in p,((lambda s,prev:[(lambda s,s2,k:[]if s2 in p else[p.__setitem__(s2,(s,k)),u.append((s2, s))])(s,tuple([(i>0 and s2[i-1])or(i<n-1 and s2[i+1])for i in range(n)]),k)for s2,k in map(lambda i:(s[:i]+(False,)+s[i+1:],i),range(n))])(*u.popleft())for _ in __import__("itertools").count()))),list(__import__('itertools').takewhile(lambda x:p[g[-1]]!=None,((b.append(p[g[-1]][1]+1),g.append(p[g[-1]][0]))for _ in __import__("itertools").count()))),print(f'{len(b)} actions'),print(*b[::-1])))({(True,)*n:None},[(False,)*n],[],__import__('collections').deque([((True,)*n,None)])))(int(input("How many cat boxes? ")))