#pragma GCC target ("avx") #pragma GCC optimize("Ofast") #pragma GCC optimize("unroll-loops") //#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native") #define _USE_MATH_DEFINES #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; using ll = long long; using ld = long double; #define int long long #define all(a) (a).begin(),(a).end() #define fs first #define sc second #define xx first #define yy second.first #define zz second.second #define H pair #define P pair> #define Q(i,j,k) mkp(i,mkp(j,k)) #define rng(i,s,n) for(int i = (s) ; i < (n) ; i++) #define rep(i,n) rng(i, 0, (n)) #define mkp make_pair #define vec vector #define vi vec #define pb emplace_back #define siz(a) (int)(a).size() #define crdcomp(b) sort(all((b)));(b).erase(unique(all((b))),(b).end()) #define getidx(b,i) (lower_bound(all(b),(i))-(b).begin()) #define ssp(i,n) (i==(int)(n)-1?"\n":" ") #define ctoi(c) (int)(c-'0') #define itoc(c) (char)(c+'0') #define cyes printf("Yes\n") #define cno printf("No\n") #define cdf(n) int quetimes_=(n);rep(qq123_,quetimes_) #define gcj printf("Case #%lld: ",qq123_+1) #define readv(a,n) a.resize(n,0);rep(i,(n)) a[i]=read() #define found(a,x) (a.find(x)!=a.end()) //#define endl "\n" constexpr int mod = (ll)1e9 + 7; constexpr int Mod = 998244353; constexpr ld EPS = 1e-10; constexpr ll inf = (ll)3 * 1e18; constexpr int Inf = (ll)15 * 1e8; constexpr int dx[] = { -1,1,0,0 }, dy[] = { 0,0,-1,1 }; templatebool chmax(T& a, const T& b) { if (a < b) { a = b; return 1; } return 0; } templatebool chmin(T& a, const T& b) { if (b < a) { a = b; return 1; } return 0; } ll read() { ll u, k = scanf("%lld", &u); return u; } string reads() { string s; cin >> s; return s; } H readh(short g = 0) { H u; int k = scanf("%lld %lld", &u.fs, &u.sc); if (g == 1) u.fs--, u.sc--; if (g == 2) u.fs--; return u; } bool ina(H t, int h, int w) { return 0 <= t.fs && t.fs < h && 0 <= t.sc && t.sc < w; } bool ina(int t, int l, int r) { return l <= t && t < r; } ll gcd(ll i, ll j) { return j ? gcd(j, i % j) : i; } ll popcount(ll x) { int sum = 0; for (int i = 0; i < 60; i++)if ((1ll << i) & x) sum++; return sum; } template class csum { vec v; public: csum(vec& a) :v(a) { build(); } csum() {} void init(vec& a) { v = a; build(); } void build() { for (int i = 1; i < v.size(); i++) v[i] += v[i - 1]; } T a(int l, int r) { if (r < l) return 0; return v[r] - (l == 0 ? 0 : v[l - 1]); }//[l,r] T b(int l, int r) { return a(l, r - 1); }//[l,r) T a(pairt) { return a(t.first, t.second); } T b(pairt) { return b(t.first, t.second); } }; class mint { public:ll v; mint(ll v = 0) { s(v % mod + mod); } constexpr static int mod = (ll)1e9 + 7; constexpr static int fn_ = (ll)2e6 + 5; static mint fact[fn_], comp[fn_]; mint pow(int x) const { mint b(v), c(1); while (x) { if (x & 1) c *= b; b *= b; x >>= 1; } return c; } inline mint& s(int vv) { v = vv < mod ? vv : vv - mod; return *this; } inline mint inv()const { return pow(mod - 2); } inline mint operator-()const { return mint() - *this; } inline mint& operator+=(const mint b) { return s(v + b.v); } inline mint& operator-=(const mint b) { return s(v + mod - b.v); } inline mint& operator*=(const mint b) { v = v * b.v % mod; return *this; } inline mint& operator/=(const mint b) { v = v * b.inv().v % mod; return *this; } inline mint operator+(const mint b) const { return mint(v) += b; } inline mint operator-(const mint b) const { return mint(v) -= b; } inline mint operator*(const mint b) const { return mint(v) *= b; } inline mint operator/(const mint b) const { return mint(v) /= b; } friend ostream& operator<<(ostream& os, const mint& m) { return os << m.v; } friend istream& operator>>(istream& is, mint& m) { int x; is >> x; m = mint(x); return is; } bool operator<(const mint& r)const { return v < r.v; } bool operator>(const mint& r)const { return v > r.v; } bool operator<=(const mint& r)const { return v <= r.v; } bool operator>=(const mint& r)const { return v >= r.v; } bool operator==(const mint& r)const { return v == r.v; } bool operator!=(const mint& r)const { return v != r.v; } explicit operator bool()const { return v; } explicit operator int()const { return v; } mint comb(mint k) { if (k > * this) return mint(); if (!fact[0]) combinit(); if (v >= fn_) { if (k > * this - k) k = *this - k; mint tmp(1); for (int i = v; i >= v - k.v + 1; i--) tmp *= mint(i); return tmp * comp[k.v]; } return fact[v] * comp[k.v] * comp[v - k.v]; }//nCk mint perm(mint k) { if (k > * this) return mint(); if (!fact[0]) combinit(); if (v >= fn_) { mint tmp(1); for (int i = v; i >= v - k.v + 1; i--) tmp *= mint(i); return tmp; } return fact[v] * comp[v - k.v]; }//nPk static void combinit() { fact[0] = 1; for (int i = 1; i < fn_; i++) fact[i] = fact[i - 1] * mint(i); comp[fn_ - 1] = fact[fn_ - 1].inv(); for (int i = fn_ - 2; i >= 0; i--) comp[i] = comp[i + 1] * mint(i + 1); } }; mint mint::fact[fn_], mint::comp[fn_]; //-------------------------------------------------------------- //--------------------------------------------------------------------- int n, m; vi a; vi e[400000]; vi f[400000]; int b[400000]; bool flag[400000]; int c[400000]; vi h[400000]; signed main() { cin >> n >> m; assert(1 <= n && n <= 1e9); assert(1 <= m && m <= 2*1e5); vecv; rep(i, m) { int c, d; cin >> c >> d; assert(1 <= c && c <= n); assert(1 <= d && d <= n); v.pb(H{ c,d }); a.pb(c); a.pb(d); } crdcomp(a); vi save = a; for (auto &g : v) { g.fs = getidx(a, g.fs); g.sc = getidx(a, g.sc); e[g.fs].pb(g.sc); f[g.sc].pb(g.fs); } rep(i, siz(a)) b[i] = -1; int idx = 0; auto dfs = [&](int x, auto& dfs) ->void{ flag[x] = 1; for (auto g : e[x]) { if (!flag[g]) dfs(g, dfs); } b[x] = idx++; }; for (int i = 0; i < siz(a); i++) { if (b[i] < 0) dfs(i, dfs); } rep(i, siz(a)) c[i] = -1; vi u; rep(i, siz(a)) u.pb(i); sort(all(u), [&](int i, int j) { return b[i] > b[j]; }); auto dfs2 = [&](int x,int y, const auto& dfs2) ->void { c[x] = y; for (auto g : f[x]) { if (c[g] == -1) dfs2(g, y, dfs2); } }; vi pos; for (auto i : u) { if (c[i] == -1) { dfs2(i, i, dfs2); pos.pb(i); } } u.clear(); u.assign(siz(a), 0); for (auto g : v) { if (c[g.fs] != c[g.sc]) { h[c[g.sc]].pb(c[g.fs]); u[c[g.fs]]++; } } rep(i, siz(a)) chmax(a[c[i]], a[i]); vi l; queueq; for (auto i : pos) { if (u[i] == 0) { q.push(i); } } while (!q.empty()) { int t = q.front(); q.pop(); l.pb(t); for (auto g : h[t]) { u[g]--; if (u[g] == 0) q.push(g); } } for (auto i: l) { for (auto g : h[i]) { chmax(a[g], a[i]); } } int ans = (1 + n) * n / 2; rep(i, siz(a)) { ans += a[c[i]] - save[i]; } cout << ans << endl; }