/** * author: shu8Cream * created: 11.06.2022 15:42:00 **/ #include using namespace std; #define overload3(a,b,c,d,...) d #define rep1(i,n) for (int i=0; i<(n); i++) #define rep2(i,a,n) for (int i=(a); i<(n); i++) #define rep(...) overload3(__VA_ARGS__, rep2, rep1)(__VA_ARGS__) #define rrep1(i,n) for (int i=(n-1); i>=0; i--) #define rrep2(i,a,n) for (int i=(n-1); i>=(a); i--) #define rrep(...) overload3(__VA_ARGS__, rrep2, rrep1)(__VA_ARGS__) #define all(x) (x).begin(), (x).end() #define rall(x) (x).rbegin(), (x).rend() #define sz(x) int((x).size()) #define pcnt __builtin_popcountll using ll = long long; using P = pair; template using vc = vector; template using vv = vc>; using vi = vc; using vvi = vv; const ll INF = 8e18; templateistream& operator>>(istream&i,vc&v){rep(j,sz(v))i>>v[j];return i;} templatestring join(const T&v,const string& d=""){stringstream s;rep(i,sz(v))(i?s<ostream& operator<<(ostream&o,const vc&v){if(sz(v))o<istream& operator>>(istream&i,pair&v){return i>>v.first>>v.second;} templateostream& operator<<(ostream&o,const pair&v){return o< inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; } template inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; } template string to_string(T s); template string to_string(pair p); string to_string(char c) { return string(1, c); } string to_string(string s) { return s; } string to_string(const char s[]) { return string(s); } template string to_string(T v) { if (v.empty()) return "{}"; string ret = "{"; for (auto x : v) ret += to_string(x) + ","; ret.back() = '}'; return ret; } template string to_string(pair p) { return "{" + to_string(p.first) + ":" + to_string(p.second) + "}"; } void debug_out() { cout << endl; } template void debug_out(Head H, Tail... T) { cout << to_string(H) << " "; debug_out(T...); } #ifdef _DEBUG #define debug(...) debug_out(__VA_ARGS__) #else #define debug(...) #endif int main() { cin.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(15); ll n,m; cin >> n >> m; vi a(n); cin >> a; map mp; rep(i,n){ ll p = min(a[i]%m,m-(a[i]%m)); if(p==a[i]%m) mp[p].first++; else mp[p].second++; } ll ans = 0; for(auto[i,pa]:mp){ if(i==0 && pa.first+pa.second>0) ans++; else if(i)ans += max(pa.first,pa.second); } if(m%2==0){ ans -= max(mp[m/2].first, mp[m/2].second); ans++; } chmax(ans,1LL); cout << ans << endl; }