#include <bits/stdc++.h>
using namespace std;

#define REP(i,n) for(ll i=0;i<(ll)n;i++)
#define dump(x)  cerr << #x << " = " << (x) << endl;
#define spa << " " <<
#define fi first
#define se second
#define ALL(a)  (a).begin(),(a).end()
#define ALLR(a)  (a).rbegin(),(a).rend()

using ld = long double;
using ll = long long;
using ull = unsigned long long;
using pii = pair<int, int>;
using pll = pair<long, long>;
using pdd = pair<ld, ld>;

template<typename T> struct V : vector<T> { using vector<T>::vector; };
V() -> V<ll>;
V(size_t) -> V<ll>;
template<typename T> V(size_t, T) -> V<T>;
template<typename T> vector<T> make_vec(size_t n, T a) { return vector<T>(n, a); }
template<typename... Ts> auto make_vec(size_t n, Ts... ts) { return vector<decltype(make_vec(ts...))>(n, make_vec(ts...)); }
template<class S, class T> ostream& operator << (ostream& os, const pair<S, T> v){os << "(" << v.first << ", " << v.second << ")"; return os;}
template<typename T> ostream& operator<<(ostream &os, const vector<T> &v) { for (auto &e : v) os << e << ' '; return os; }
template<class T> ostream& operator<<(ostream& os, const vector<vector<T>> &v){ for(auto &e : v){os << e << "\n";} return os;}
struct fast_ios { fast_ios(){ cin.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(20); }; } fast_ios_;

template<class T> bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T> bool chmin(T &a, const T &b) { if (a>b) { a=b; return 1; } return 0; }
void fail() { cout << -1 << '\n'; exit(0); }
inline int popcount(const int x) { return __builtin_popcount(x); }
inline int popcount(const ll x) { return __builtin_popcountll(x); }
template<typename T> void debug(vector<vector<T>>&v,ll h,ll w){for(ll i=0;i<h;i++)
{cerr<<v[i][0];for(ll j=1;j<w;j++)cerr spa v[i][j];cerr<<endl;}};
template<typename T> void debug(vector<T>&v,ll n){if(n!=0)cerr<<v[0];
for(ll i=1;i<n;i++)cerr spa v[i];
cerr<<endl;};

const ll INF = (1ll<<62);
// const ld EPS   = 1e-10;
// const ld PI    = acos(-1.0);
const ll mod = (int)1e9 + 7;
//const ll mod = 998244353;
using Graph = V<V<ll>>;

template< typename G >
struct StronglyConnectedComponents {
  const G &g;
  Graph gg, rg;
  vector< int > comp, order, used;

  StronglyConnectedComponents(G &g) : g(g), gg(g.size()), rg(g.size()), comp(g.size(), -1), used(g.size()) {
    for(int i = 0; i < (int)g.size(); i++) {
      for(auto e : g[i]) {
        gg[i].emplace_back((int) e);
        rg[(int) e].emplace_back(i);
      }
    }
  }

  int operator[](int k) {
    return comp[k];
  }

  void dfs(int idx) {
    if(used[idx]) return;
    used[idx] = true;
    for(int to : gg[idx]) dfs(to);
    order.push_back(idx);
  }

  void rdfs(int idx, int cnt) {
    if(comp[idx] != -1) return;
    comp[idx] = cnt;
    for(int to : rg[idx]) rdfs(to, cnt);
  }

  void build(Graph &t) {
    for(int i = 0; i < (int)gg.size(); i++) dfs(i);
    reverse(begin(order), end(order));
    int ptr = 0;
    for(int i : order) if(comp[i] == -1) rdfs(i, ptr), ptr++;

    t.resize(ptr);
    for(int i = 0; i < (int)g.size(); i++) {
      for(auto &to : g[i]) {
        int x = comp[i], y = comp[to];
        if(x == y) continue;
        t[x].push_back(y);
      }
    }
  }
};

int main(){

    ll N, M;
    cin >> N >> M;
    ll res = 0;
    res += N * (N+1) / 2;

    V<ll> B(M), C(M);
    REP(i, M){
        cin >> B[i] >> C[i];
    }
    set<ll> st;
    REP(i, M){
        st.insert(B[i]);
        st.insert(C[i]);
    }
    map<ll, ll> mp;
    ll cnt = 0;
    V<ll> score;
    for(auto x: st){
        mp[x] = cnt;
        score.push_back(x);
        cnt++;
        res -= x;
    }
    ll K = cnt;
    Graph G(K), T;
    REP(i, M){
        G[mp[B[i]]].push_back(mp[C[i]]);
    }

    for(auto &v: G){
        sort(ALL(v));
        v.erase(unique(ALL(v)), v.end());
    }

    StronglyConnectedComponents<Graph> scc(G);
    scc.build(T);

    ll S = T.size();
    for(auto &v: T){
        sort(ALL(v));
        v.erase(unique(ALL(v)), v.end());
    }

    V<ll> ma(S, 0), sz(S, 0);
    REP(i, K){
        chmax(ma[scc[i]], score[i]);
        sz[scc[i]]++;
    }

    V<ll> dp(S, -1);

    // dump(S)

    auto rec = [&](auto self, ll now){
        if(dp[now]>=0) return dp[now];
        ll val = ma[now];
        for(auto next: T[now]){
            ll tmp = self(self, next);
            chmax(val, tmp);
        }
        dp[now] = val;
        res += val * sz[now];
        return val;
    };

    REP(i, S) rec(rec, i);

    cout << res << endl;

    return 0;
}