[{"sectionTitle":"题目描述","type":"Text","text":"原题来自：NOIP 2012 普及组\r\n\r\n已知正整数 $n$ 是两个不同的质数的乘积，试求出较大的那个质数。","subType":"markdown"},{"sectionTitle":"输入格式","type":"Text","text":"输入只有一行，包含一个正整数 $n$。","subType":"markdown"},{"sectionTitle":"输出格式","type":"Text","text":"输出只有一行，包含一个正整数 $p$，即较大的那个质数。","subType":"markdown"},{"sectionTitle":"样例","type":"Sample","text":"","subType":"markdown","payload":["21","7"]},{"sectionTitle":"数据范围与提示","type":"Text","text":"对于 $30\\%$ 的数据，$n\\le 1000$； \r\n对于全部数据，$6\\le n\\le 2\\times 10^9$。","subType":"markdown"}]