#ifdef DEBUG #include"stdlibrary.h" #else #pragma GCC target("avx") #pragma GCC optimize("O3") #pragma GCC optimize("unroll-loops") #include using namespace std; #endif // #include // #include // #include // using namespace __gnu_pbds; // #include // namespace multiprecisioninteger = boost::multiprecision; // using cint=multiprecisioninteger::cpp_int; using ll=long long; using datas=pair; using ddatas=pair; using tdata=pair; using vec=vector; using mat=vector; using pvec=vector; using pmat=vector; // using llset=tree,rb_tree_tag,tree_order_statistics_node_update>; #define For(i,a,b) for(i=a;i<(ll)b;++i) #define bFor(i,b,a) for(i=b,--i;i>=(ll)a;--i) #define rep(i,N) For(i,0,N) #define rep1(i,N) For(i,1,N) #define brep(i,N) bFor(i,N,0) #define brep1(i,N) bFor(i,N,1) #define all(v) (v).begin(),(v).end() #define allr(v) (v).rbegin(),(v).rend() #define vsort(v) sort(all(v)) #define vrsort(v) sort(allr(v)) #define uniq(v) vsort(v),(v).erase(unique(all(v)),(v).end()) #define endl "\n" #define popcount __builtin_popcountll #define eb emplace_back #define print(x) cout< ostream& operator<<(ostream& os,const pair& p){return os<<"("< ostream& operator<<(ostream& os,const vector& v){ os<<"{";bool f=false; for(auto& x:v){if(f)os<<",";os< ostream& operator<<(ostream& os,const set& v){ os<<"{";bool f=false; for(auto& x:v){if(f)os<<",";os< ostream& operator<<(ostream& os,const multiset& v){ os<<"{";bool f=false; for(auto& x:v){if(f)os<<",";os< ostream& operator<<(ostream& os,const map& v){ os<<"{";bool f=false; for(auto& x:v){if(f)os<<",";os< inline bool chmax(T& a,const T b){bool x=a inline bool chmin(T& a,const T b){bool x=a>b;if(x)a=b;return x;} #ifdef DEBUG void debugg(){cout<void debugg(const T& x,const Args&... args){cout<<" "<sync_with_stdio(0); cout<size;--i)modncrlistm[i-1]=modncrlistm[i]*i%mod; } return modncrlistp[n]*modncrlistm[r]%mod*modncrlistm[n-r]%mod; } ll modpow(ll a,ll n,const ll m=mod){ if(n<0)return 0; ll res=1; while(n>0){ if(n&1)res=res*a%m; a=a*a%m; n>>=1; } return res; } constexpr ll gcd(const ll a,const ll b) noexcept{return (!b)?abs(a):(a%b==0)?abs(b):gcd(b,a%b);} constexpr ll lcm(const ll a,const ll b) noexcept{return a/gcd(a,b)*b;} // #include // using mint=atcoder::modint1000000007; // void operator>>(istream& is,mint& v){long long x;is>>x;v=x;} // ostream& operator<<(ostream& os,const mint& v){return os< struct BinaryIndexedTree{ int size,bitn=0; T I; using func=function; func F; vector tree; BinaryIndexedTree(int N,T e,func f):size(N+1),I(e),F(f),tree(size,e){} BinaryIndexedTree(int N):size(N+1),I(),F([](T a,T b){return a+b;}),tree(size){} void act(int i,T x){ for(++i;i0;i-=-i&i){ res=F(tree[i],res); } return res; } //sum([l,r)); T sum(int l,int r){ // if(--l>--r)return 0; assert(--l<=--r); if(l<0)return query(r); else return query(r)-query(l); } //only(N,+) int lower_bound(int x){ int i=0; if(!bitn){ i=size;bitn=1; while(i){ i>>=1;bitn<<=1; } i=0; } for(int k=bitn;k;k>>=1){ if(i+k>codeforces;while(codeforces--){ ll i,j; cin>>N>>M; vec p(M),m(M); rep(i,M){ cin>>A>>B; p[i]=A+B; m[i]=A-B; } uniq(p); uniq(m); vec ch[2]; for(auto& x:p){ ans+=N-abs(N+1-x); ch[x&1].emplace_back(x); } for(auto& x:m){ ans+=N-abs(x); if(x>=0){ //(1+x,1),(N,N-x) ans-=upper_bound(all(ch[x&1]),2*N-x)-lower_bound(all(ch[x&1]),2+x); }else{ //(1,1-x),(N+x,N); ans-=upper_bound(all(ch[x&1]),2*N+x)-lower_bound(all(ch[x&1]),2-x); } } print(ans); }