#include <iostream>
#include <algorithm>
#include <string>
#include <vector>
#include <cmath>
#include <map>
#include <queue>
#include <iomanip>
#include <set>
#include <tuple>
#define mkp make_pair
#define mkt make_tuple
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define all(v) v.begin(),v.end()
using namespace std;
typedef long long ll;
const ll MOD=1e9+7;
template<class T> void chmin(T &a,const T &b){if(a>b) a=b;}
template<class T> void chmax(T &a,const T &b){if(a<b) a=b;}

/* example
    int n=scc.scc();
    scc.build(n,g);
    (g:outside)
*/
struct StronglyConnectedComponents{
    vector<int> used,cmp,vs;
    vector<vector<int>> ori;
    vector<vector<int>> v,rv;
    StronglyConnectedComponents(int n):used(n),cmp(n,-1),v(n),rv(n){}
 
    void add_edge(int x,int y){
        v[x].push_back(y);
        rv[y].push_back(x);
    }
    void dfs(int x){
        used[x]=true;
        for(auto to:v[x]) if(!used[to]) dfs(to);
        vs.push_back(x);
    }
 
    void rdfs(int x,int k){
        cmp[x]=k;
        for(auto to:rv[x]) if(cmp[to]==-1) rdfs(to,k);
    }
 
    int scc(){
        for(int i=0;i<used.size();i++) if(!used[i]) dfs(i);
        reverse(vs.begin(),vs.end());
        int k=0;
        for(auto x:vs) if(cmp[x]==-1) rdfs(x,k++);

        ori.resize(k);
        for(int i=0;i<used.size();i++) ori[cmp[i]].push_back(i);

        return k;//k:size
    }

    void build(int k,vector<vector<int>> &g){
        g.resize(k);
        for(int i=0;i<v.size();i++){
            for(auto to:v[i]){
                int x=cmp[i],y=cmp[to];
                if(x!=y) g[x].push_back(y);
            }
        }
    }
};

vector<vector<int>> g;
vector<int> vis;
vector<int> dp;
vector<ll> B,C;

void dfs(int now){
  if(vis[now]) return;
  for(auto nex:g[now]){
    dfs(nex);
    chmax(dp[now],dp[nex]);
  }
  vis[now]=1;
}

int main(){
  cin.tie(0);
  ios::sync_with_stdio(false);

  ll N,M;
  cin>>N>>M;
  B.resize(M);
  C.resize(M);
  rep(i,M) cin>>B[i]>>C[i];

  vector<int> v;
  rep(i,M) v.push_back(B[i]);
  rep(i,M) v.push_back(C[i]);
  sort(all(v));
  v.erase(unique(all(v)),v.end());
  int V=v.size();
  map<int,int> mp;
  rep(i,V) mp[v[i]]=i;
  
  StronglyConnectedComponents scc(V);
  rep(i,M){
    scc.add_edge(mp[B[i]],mp[C[i]]);
  }
  int S=scc.scc();
  scc.build(S,g);

  dp.resize(S,0);
  for(int i=0;i<V;i++) chmax(dp[scc.cmp[i]],v[i]);
  vis.resize(S,0);
  for(int i=0;i<S;i++){
    if(vis[i]) continue;
    dfs(i);
  }

  ll ans=N*(N+1)/2;
  for(int i=0;i<V;i++){
    ans-=v[i];
    ans+=dp[scc.cmp[i]];
  }
  cout<<ans<<endl;

  return 0;
}