Given an array $a$ with length $n$, could you tell me how many pairs $(i,j)$ ( i < j ) for $abs(a_i-a_j) \ mod \ b = c$.
Several test cases(about $5$)
For each cases, first come 3 integers, $n,b,c(1 \leq n \leq 100,0 \leq c < b \leq 10^9)$
Then follows $n$ integers $a_i ( 0 \leq a_i \leq 10^9)$
For each cases, please output an integer in a line as the answer.