{"trustable":false,"sections":[{"title":"题面描述:","value":{"format":"MD","content":"哥德巴赫猜想的内容为,任何一个大于等于 4 的偶数 x,总能被表示成两个质数的和。当 x \u003c\u003d 10^6 时,我们可以验证猜想是正确的。\n\n定义哥德巴赫步骤为,将一个 x (4 \u003c\u003d x \u003c\u003d 10^6),找到两个和为 x 的质数 p, q (p \u003c\u003d q) ,然后用 q - p 代替 x ,如果存在多对质数满足和为 x ,则去 q - p 最大的质数对。 根据定义我们可知, q - p 一定是小于 x 的偶数。因此我们可以重复进行哥德巴赫步骤,直到我们得到一个小于 4 的数。\n\n给定 x,请问 x 进行几次哥德巴赫步骤之后,才能得到一个小于 4 的数。\n\n"}},{"title":"输入:","value":{"format":"MD","content":"输入为一个偶数 x (4 \u003c\u003d x \u003c\u003d 10^6)"}},{"title":"输出:","value":{"format":"MD","content":"输出一个整数,表示想要得到一个小于 4 的数, x 需要进行的哥德巴赫步骤的次数。"}},{"title":"样例 1 输入:","value":{"format":"MD","content":"20"}},{"title":"样例 1 输出:","value":{"format":"MD","content":"3"}},{"title":"样例 2 输入:","value":{"format":"MD","content":"30"}},{"title":"样例 2 输出:","value":{"format":"MD","content":"4"}},{"title":"样例 3 输入:","value":{"format":"MD","content":"40"}},{"title":"样例 3 输出:","value":{"format":"MD","content":"5"}},{"title":"样例 4 输入:","value":{"format":"MD","content":"50"}},{"title":"样例 4 输出:","value":{"format":"MD","content":"6"}},{"title":"样例 5 输入:","value":{"format":"MD","content":"60"}},{"title":"样例 5 输出:","value":{"format":"MD","content":"7"}},{"title":"样例 6 输入:","value":{"format":"MD","content":"70"}},{"title":" 样例 6 输出:","value":{"format":"MD","content":"8"}}]}