{"trustable":false,"sections":[{"title":"","value":{"format":"HTML","content":"\n \u003cdiv class\u003d\"ptx\" lang\u003d\"en-US\"\u003e\n 甲 和 乙喜欢思考一个游戏,有N堆石子,第 i 堆有 ai 个,你每次可以将某一堆的任意数量的石子丢弃,轮流进行这种操作,面对没有石子可以丢弃石子的局面为败。问你有几种必胜的初始取法。\n \u003c/div\u003e"}},{"title":"Input","value":{"format":"HTML","content":"\n \u003cdiv class\u003d\"ptx\" lang\u003d\"en-US\"\u003e\n 多组样例。\n 每组样例首行一个N,下一行接N个数字,第 i 个为ai,意义如上。\n \u003c/div\u003e"}},{"title":"Output","value":{"format":"HTML","content":"\n \u003cdiv class\u003d\"ptx\" lang\u003d\"en-US\"\u003e\n \u003cp\u003e你有几种必胜的初始取法数\u003c/p\u003e\n \u003c/div\u003e"}},{"title":"Sample Input","value":{"format":"HTML","content":"\u003cpre class\u003d\"sio\"\u003e\n3\n7 11 13\n0\u003c/pre\u003e"}},{"title":"Sample Output","value":{"format":"HTML","content":"\u003cpre class\u003d\"sio\"\u003e\n3\u003c/pre\u003e"}}]}