fn divisibleSumPairs(n: i32, k: i32, ar: &[i32]) -> i32 {
    let mut x = 1;
    let mut n_pairs = 0;
    
    for &i in ar {
        for &j in &ar[x..] {
            if (i + j) % k == 0 {
                n_pairs += 1;
            }
        }
        x += 1;
    }
    n_pairs
}