#include #include #define rep(i,b) for(int i=0;i=0;i--) #define rep1(i,b) for(int i=1;i using mpq = priority_queue, greater>; template bool chmax(T &a, const T &b) { if (a bool chmin(T &a, const T &b) { if (b ll sumv(const vector&a){ll res(0);for(auto&&x:a)res+=x;return res;} bool yn(bool a) { if(a) {cout << "Yes" << endl; return 1;} else {cout << "No" << endl; return 0;}} #define dame { cout << "No" << endl; return 0;} #define dame1 { cout << -1 << endl; return 0;} #define test(x) cout << "test" << x << endl; #define deb(x,y) cout << x << " " << y << endl; #define deb3(x,y,z) cout << x << " " << y << " " << z << endl; #define deb4(x,y,z,x2) cout << x << " " << y << " " << z << " " << x2 << endl; #define out cout << ans << endl; #define outv fore(yans , ans) cout << yans << "\n"; #define show(x) cerr<<#x<<" = "<; using pil = pair; using pli = pair; using pii = pair; using tp = tuple; using vi = vector; using vl = vector; using vs = vector; using vb = vector; using vpii = vector; using vpli = vector; using vpll = vector; using vpil = vector; using vvi = vector>; using vvl = vector>; using vvs = vector>; using vvb = vector>; using vvpii = vector>; using vvpli = vector>; using vvpll = vector; using vvpil = vector; using mint = modint998244353; using vm = vector; using vvm = vector>; vector dx={1,0,-1,0,1,1,-1,-1},dy={0,1,0,-1,1,-1,1,-1}; ll gcd(ll a, ll b) { return a?gcd(b%a,a):b;} ll lcm(ll a, ll b) { return a/gcd(a,b)*b;} const double eps = 1e-10; const ll LINF = 1001002003004005006ll; const int INF = 1001001001; int main(){ ll n,m; cin>>n>>m; map mpr,mpc; rep(i,m){ ll a,b; cin>>a>>b; a--; b--; ll x = a+b; ll y = a-b; mpr[x] = 0; mpc[y] = 0; } ll ans = 0; vvl vr(2); fore(y , mpc){ ans += n - abs(y.fi); } fore(y , mpr){ vr[abs(y.fi)%2].pb(y.fi); ans += n - abs(y.fi - n + 1); } ll sum = 0; fore(y , mpc){ // show(y.fi); ll parity = abs(y.fi) % 2; ll sum2 = 0; ll lk = abs(y.fi); ll l = -lk + (ll)2 * n - 2; // deb(l , y.fi); ll k = vr[parity].end() - upper_bound(rng(vr[parity]) , l); sum2 += k; l = lk; k = lower_bound(rng(vr[parity]) , l) - vr[parity].begin(); sum2 += k; // if (lk == n-1) sum2--; // show(sz(vr[parity]) - sum2); sum += (sz(vr[parity]) - sum2); // deb(sum , y.fi); } // fore(y , mpr){ // ll l = n - 1 + y.fi; // ll k = vr.end() - lower_bound(rng(vr) , l); // sum += k; // l = n - 1 - y.fi; // k = upper_bound(rng(vr) , l) - vr.begin(); // sum += k; // } ans -= sum; out; return 0; }