#include #include #include using namespace std; using namespace atcoder; using mint = modint998244353; #define rep(i,n) for (int i = 0; i < (n); ++i) #define Inf32 1000000001 #define Inf64 4000000000000000001 int main(){ int n,m; cin>>n>>m; vector a(n); rep(i,n){ cin>>a[i]; a[i] %= m; } sort(a.begin(),a.end()); long long ans = 0; rep(i,n){ if(m%2==0 && binary_search(a.begin(),a.end(),a[i] + m/2))ans += n-2; } cout<