//#define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
#define rep(i, n) for(int i=0; i<n; ++i)
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
using namespace std;
using ll = int64_t;
using ld = long double;
using P = pair<int, int>;
using vs = vector<string>;
using vi = vector<int>;
using vvi = vector<vi>;
template<class T> using PQ = priority_queue<T>;
template<class T> using PQG = priority_queue<T, vector<T>, greater<T> >;
const int INF = 0xccccccc;
const ll LINF = 922337203685477580LL;
template<typename T1, typename T2>
inline bool chmax(T1 &a, T2 b) {return a < b && (a = b, true);}
template<typename T1, typename T2>
inline bool chmin(T1 &a, T2 b) {return a > b && (a = b, true);}
template<typename T1, typename T2>
istream &operator>>(istream &is, pair<T1, T2> &p) { return is >> p.first >> p.second;}
template<typename T1, typename T2>
ostream &operator<<(ostream &os, const pair<T1, T2> &p) { return os << p.first << ' ' << p.second;}

struct UnionFind {
  vector<int> par; // 親を指すvector,-par[親]は木のサイズ
  UnionFind(int n):par(n, -1) {} // uniteで親を埋め込んでいく必要あり
  int root(int x) { // 親をたどる&データの整理
    if(par[x] < 0) return x;
    return par[x] = root(par[x]);
  }
  bool unite(int x, int y) { // データの結合
    x = root(x);
    y = root(y);
    if(x == y) return false;
    if(x < y) swap(x, y);
    par[x] += par[y];
    par[y] = x;
    return true;
  }
  bool same(int x, int y) {return root(x) == root(y);} // 所属判定
  int size(int x) {return -par[root(x)];} // 木のサイズ
};

#define M 200100
#define MM 400100

//head

int n, m, X;
int b[M], c[M];
ll ans;
stack<int> st;
bitset<MM> check;
vi xs, G[MM], rG[MM];
vi Graph[MM];
UnionFind uft(MM);
int memo[MM];

void dfs1(int i) {
  for(int ne:G[i]) if(!check.test(ne)) {
    check.set(ne);
    dfs1(ne);
  }
  st.emplace(i);
}
void dfs2(int i) {
  for(int ne:rG[i]) if(check.test(ne)) {
    check.flip(ne);
    uft.unite(i, ne);
    dfs2(ne);
  }
}
int dfs3(int i) {
  if(memo[i] != -1) return memo[i];
  int &res = memo[i] = xs[i];
  for(int ne:Graph[i]) {
    chmax(res, dfs3(ne));
  }
  ans += res-xs[i];
  return res;
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cin >> n >> m;
  ans = (ll)n*(n+1)>>1;
  rep(i, m) cin >> b[i] >> c[i];

  auto compress = [&](int *x1, int *x2) {
    rep(i_, m) {
      xs.push_back(x1[i_]);
      xs.push_back(x2[i_]);
    }
    sort(all(xs));
    xs.erase(unique(all(xs)), xs.end());
    rep(i_, m) {
      x1[i_] = lower_bound(all(xs), x1[i_]) - xs.begin();
      x2[i_] = lower_bound(all(xs), x2[i_]) - xs.begin();
    }
  };
  
  compress(b, c);
  
  X = xs.size();

  rep(i, m) {
    G[b[i]].emplace_back(c[i]);
    rG[c[i]].emplace_back(b[i]);
  }

  rep(i, X) if(!check.test(i)) {
    check.set(i);
    dfs1(i);
  }
  while(!st.empty()) {
    int now = st.top();
    st.pop();
    if(check.test(now)) {
      check.flip(now);
      dfs2(now);
    }
  }
  rep(i, X) {
    int u = i;
    if(uft.root(u) != i) {
      u = uft.root(u);
      Graph[i].emplace_back(u);
    }
    for(int ne:G[i]) {
      if(uft.root(ne) == u) continue;
      Graph[u].emplace_back(uft.root(ne));
    }
  }
  memset(memo, -1, sizeof(memo));
  rep(i, X) {
    dfs3(i);
  }

  cout << ans << endl;
}