【文件属性】：
文件名称：HDU 2136 Largest prime factor
文件大小：151KB
文件格式：EXE
更新时间：2018-07-09 10:55:35
Largest prime factor
Largest prime factor
Everybody knows any number can be combined by the prime number.
Now, your task is telling me what position of the largest prime factor.
The position of prime 2 is 1, prime 3 is 2, and prime 5 is 3, etc.
Specially, LPF(1) = 0.
Each line will contain one integer n(0 < n < 1000000).
Output the LPF(n).