#include using namespace std; using ll=long long; using pll=pair; using tll=tuple; using ld=long double; const ll INF=(1ll<<60); #define rep(i,n) for(ll i=0;i<(ll)(n);i++) #define all(v) v.begin(),v.end() template void chmin(T &a,T b){ if(a>b){ a=b; } } template void chmax(T &a,T b){ if(a> n >> m; vector a(n); rep(i,n) cin >> a[i]; if(m%2==1){ cout << "0\n"; return 0; } map mp; rep(i,n){ mp[a[i]%m]++; } ll ans=0; for(auto &[k,v]:mp){ ll x=(k+m/2)%m; if(k==x) continue; if(mp.find(x)==mp.end()) continue; ans+=v*mp[x]*(n-2); } cout << ans/2 << '\n'; }