#pragma GCC optimize("O3") #include using namespace std; using ll=long long; using P=pair; template using V=vector; #define fi first #define se second #define all(v) (v).begin(),(v).end() const ll inf=(1e18); // const ll mod=998244353; const ll mod=1000000007; const vector dy={-1,0,1,0},dx={0,-1,0,1}; struct __INIT{__INIT(){cin.tie(0);ios::sync_with_stdio(false);cout< bool chmax(T &a, const T &b) { if (a bool chmin(T &a, const T &b) { if (a>b) { a=b; return 1; } return 0; } templatevoid debag(const vector &a){cerr<<"debag :";for(auto v:a)cerr<void print(const vector &a){for(auto v:a)cout<>n>>m; ll ans=0; map mp,cp; for(int i=0;i>a; mp[a%m]++; cp[a%m]++; } for(auto [t,v]:mp){ ll b=(m-t); if(b>=m)b-=m; if(t==b){ ans++; continue; } if(cp.count(b)){ if(t>b)continue; ans+=max(v,cp[b]); }else{ ans+=v; } } cout<