#include <bits/stdc++.h>
using namespace std;
using ll=long long;
using vin=vector<int>;
using vll=vector<long long>;
using vvin=vector<vector<int>>;
using vvll=vector<vector<long long>>;
using vstr=vector<string>;
using vvstr=vector<vector<string>>;
using vch=vector<char>;
using vvch=vector<vector<char>>;
using vbo=vector<bool>;
using vvbo=vector<vector<bool>>;
using vpii=vector<pair<int,int>>;
using pqsin=priority_queue<int,vector<int>,greater<int>>;
#define mp make_pair
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define rep2(i,s,n) for(int i=(s);i<(int)(n);i++)
#define all(v) v.begin(),v.end()
#define decp(n) cout<<fixed<<setprecision((int)n)
const ll inf=1e9+7;
const ll INF=1e18;
const ll mod=998244353;

map<ll,vll> edge;
map<ll,ll> num;

ll dfs(ll s){
    if(num[s]!=-1)return num[s];
    num[s]=s;
    for(auto& e:edge[s])num[s]=max(num[s],dfs(e));
    return num[s];
}

int main(){
    ll n;int m;cin>>n>>m;
    vll b(m),c(m);
    rep(i,m){
        cin>>b[i]>>c[i];
        edge[b[i]].push_back(c[i]);
        num[b[i]]=-1;num[c[i]]=-1;
    }
    ll ans=n*(n+1)/2;
    rep(i,m)ans+=dfs(b[i])-b[i];
    cout<<ans<<endl;
}