1527 - Pseudoprime numbers

Time Limit : 1 Second

Memory Limit : 128 MB

Submission: 14

Solved: 4

Description
Fermat's theorem states that for any prime number p and for any integer a > 1ap == a (mod p). That is, if we raise a to the pth power and divide byp, the remainder is a. Some (but not very many) non-prime values of p, known as base-a pseudoprimes, have this property for some a. (And some, known as Carmichael Numbers, are base-a pseudoprimes for all a.)

Given 2 < p ≤ 1,000,000,000 and 1 < a < p, determine whether or not p is a base-a pseudoprime.


Input
Input contains several test cases followed by a line containing "0 0". Each test case consists of a line containing p and a
Output
For each test case, output "yes" if p is a base-a pseudoprime; otherwise output "no".
sample input
3 2
10 3
341 2
341 3
1105 2
1105 3
0 0
sample output
no
no
yes
no
yes
yes
hint
source
waterloo 23 September, 2007
© 2015 HUST ACMICPC TEAM. All Right Reserved.