spoj#FUNMODSEQ. Funny Modular Sequence
Funny Modular Sequence
Lets define a funny modular sequence as a sequence such that a1 x a2=1 (mod p), a2 x a3=1 (mod p) ..., an-1 x an = 1 (mod p). Also, a1, a 2, a 3, ... an must be less than p and greater than or equal to 0. Given one element, a1, find the sum of the entire funny modular sequence of length n. If, for any ai, where i>=1, there exists no ai+1 such that aix ai+1 = 1 (mod p), output -1.
Note: p is not necessarily prime.
Input:
The first line contains T, the number of test cases.
T lines follow, each containing a1, p, and n.
Output:
For each test case, output one line, the required sum.
Constraints:
1<=T<=105
1<=a1<=105
1<=n<=109
a1 < p <=109
Sample Input:
2
2 3 2
3 7 2
Sample Output:
4
8
Explanation
In the first test case, the funny modular sequence will be 2, 2, which has a sum of 4.
In the second test case, it will be 3, 5, which has a sum of 8.