2^x mod n = 1 acm竞赛题 Give a number n, find the minimum x that satisfies 2^x mod n = 1. Input One positive integer on each line, the value of n. Output If the minimum x exists, print a line with 2^x mod n = 1. Print 2^? mod n = 1 otherwise. You should replace x and n with specific numbers. Sample Input 2 5 Sample Output 2^? mod 2 = 1 2^4 mod 5 = 1