using System;
using System.Collections.Generic;
using System.Collections;
using System.Collections.Specialized;
using System.Linq;
using System.Text;
using System.IO;
using System.Reflection;
using static System.Math;
using System.Numerics;
static class Program{
	const int mod=(int)1e9+7;
	static List<int>[] li,lir,lid;
	static bool[] b;
	static int k=0,m=0;
	static int[] h,zt,za,ma;
	static void Main(){
		Sc sc=new Sc();
		var s=sc.Ia;
		var hs=new Dictionary<int,int>();
		var g=new int[s[1]][];
		int z=0;
		for(int i=0;i<s[1];i++){
			var e=sc.Ia;
			if(!hs.ContainsKey(e[0])){hs[e[0]]=++z;}
			if(!hs.ContainsKey(e[1])){hs[e[1]]=++z;}
			g[i]=new int[]{hs[e[0]],hs[e[1]]};
		}
		li=new List<int>[z+1];
		lir=new List<int>[z+1];
		b=new bool[z+1];
		k=z-1;
		za=new int[z+1];
		foreach(var e in hs){za[e.Value]=e.Key;}
		for(int i=1;i<=z;i++){li[i]=new List<int>();lir[i]=new List<int>();}
		for(int i=0;i<s[1];i++){
			li[g[i][0]].Add(g[i][1]);
			lir[g[i][1]].Add(g[i][0]);
		}
		h=new int[z];
		for(int i=1;i<=z;i++){if(!b[i]){Fu1(i);}}
		b=new bool[z+1];
		zt=new int[z+1];
		for(int i=0;i<z;i++){
			if(!b[h[i]]){
				m++;
				Fu2(h[i]);
			}
		}
		lid=new List<int>[m+1];
		for(int i=1;i<=m;i++){lid[i]=new List<int>();}
		for(int i=1;i<=z;i++){
			for(int j=0;j<li[i].Count;j++){if(zt[i]!=zt[li[i][j]]){lid[zt[i]].Add(zt[li[i][j]]);}}
		}
		for(int i=1;i<=m;i++){lid[i]=lid[i].Distinct().ToList();}
		ma=new int[m+1];
		for(int i = 1;i<=z;i++) {ma[zt[i]]=Max(ma[zt[i]],za[i]);}
		b=new bool[m+1];
		h=new int[m+1];
		Fu3(1);
		long ans=Ap(1,1,s[0]);
		for(int i = 1;i<=z;i++) {ans+=ma[zt[i]]-za[i];}
		Console.WriteLine(ans);
	}
	static long Ap(long a,long d,long n){return (n*((a<<1)+(n-1)*d))>>1;}
	static void Fu3(int a){
		b[a]=true;
		for(int i=0;i<lid[a].Count;i++){
			if(!b[lid[a][i]]){
				Fu3(lid[a][i]);
				ma[a]=Max(ma[a],ma[lid[a][i]]);
			}
		}
	}
	static void Fu1(int a){
		b[a]=true;
		for(int i=0;i<li[a].Count;i++){if(!b[li[a][i]]){Fu1(li[a][i]);}}
		h[k]=a;
		k--;
	}
	static void Fu2(int a){
		zt[a]=m;
		b[a]=true;
		for(int i=0;i<lir[a].Count;i++){if(!b[lir[a][i]]){Fu2(lir[a][i]);}}
	}
}

public class Sc{
	public int I{get{return int.Parse(Console.ReadLine());}}
	public long L{get{return long.Parse(Console.ReadLine());}}
	public double D{get{return double.Parse(Console.ReadLine());}}
	public string S{get{return Console.ReadLine();}}
	public int[] Ia{get{return Array.ConvertAll(Console.ReadLine().Split(),int.Parse);}}
	public long[] La{get{return Array.ConvertAll(Console.ReadLine().Split(),long.Parse);}}
	public double[] Da{get{return Array.ConvertAll(Console.ReadLine().Split(),double.Parse);}}
	public string[] Sa{get{return Console.ReadLine().Split();}}
	public object[] Oa{get{return Console.ReadLine().Split();}}
	public int[] Ia2{get{return Array.ConvertAll(("0 "+Console.ReadLine()+" 0").Split(),int.Parse);}}
	public int[] Ia3(string a,string b){return Array.ConvertAll((a+Console.ReadLine()+b).Split(),int.Parse);}
	public long[] La2{get{return Array.ConvertAll(("0 "+Console.ReadLine()+" 0").Split(),long.Parse);}}
	public long[] La3(string a,string b){return Array.ConvertAll((a+Console.ReadLine()+b).Split(),long.Parse);}
	public double[] Da2{get{return Array.ConvertAll(("0 "+Console.ReadLine()+" 0").Split(),double.Parse);}}
	public double[] Da3(string a,string b){return Array.ConvertAll((a+Console.ReadLine()+b).Split(),double.Parse);}
	public T[] Arr<T>(int n,Func<T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f();}return a;}
	public T[] Arr<T>(int n,Func<int,T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(i);}return a;}
	public T[] Arr<T>(int n,Func<string[],T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(Console.ReadLine().Split());}return a;}
	public T[] Arr<T>(int n,Func<int,string[],T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(i,Console.ReadLine().Split());}return a;}
}