using System;
using System.Collections;
using System.Collections.Generic;
 
class TEST{
	static void Main(){
		Sol mySol =new Sol();
		mySol.Solve();
	}
}

class Sol{
	public void Solve(){
		T=new int[N];
		for(int i=0;i<N;i++)T[i]=i;
		for(int i=0;i<Ec;i++){
			swap(ref T[A[i][0]-1],ref T[A[i][1]-1]);
		}
//for(int i=0;i<N;i++)Console.Write("{0} ",T[i]);Console.WriteLine();
		used=new bool[N];
		compo=new int[N];
		int c=0;
		for(int i=0;i<N;i++){
			if(!used[i])dfs(i,++c);
		}
//for(int i=0;i<N;i++)Console.Write("{0} ",compo[i]);Console.WriteLine();
		
		Dictionary<int,int> D=new Dictionary<int,int>();
		for(int i=0;i<N;i++){
			if(!D.ContainsKey(compo[i]))D.Add(compo[i],0);
			D[compo[i]]++;
		}
		
		int ans=1;
		foreach(var k in D.Keys){
//Console.WriteLine("{0}:{1}",k,D[k]);
			ans=lcm(ans,D[k]);
		}
		Console.WriteLine(ans);
		
	}
	
	int[] T;
	bool[] used;
	int[] compo;
	
	void dfs(int now,int c_){
		compo[now]=c_; 
		used[now]=true;
		if(!used[T[now]])dfs(T[now],c_);
	}
	
	int gcd(int a,int b){
		return a==0?b:gcd(b%a,a);
	}
	
	int lcm(int a,int b){
		return a*b/gcd(a,b);
	}
	int N;
	int[][] A;
	int Ec;
	public Sol(){
		N=ri();
		Ec=ri();
		A=new int[Ec][];
		for(int i=0;i<Ec;i++){
			A[i]=ria();
		}
	}

	void swap(ref int a,ref int b){
		int t=a;a=b;b=t;
	}


	static String rs(){return Console.ReadLine();}
	static int ri(){return int.Parse(Console.ReadLine());}
	static long rl(){return long.Parse(Console.ReadLine());}
	static double rd(){return double.Parse(Console.ReadLine());}
	static String[] rsa(){return Console.ReadLine().Split(' ');}
	static int[] ria(){return Array.ConvertAll(Console.ReadLine().Split(' '),e=>int.Parse(e));}
	static long[] rla(){return Array.ConvertAll(Console.ReadLine().Split(' '),e=>long.Parse(e));}
	static double[] rda(){return Array.ConvertAll(Console.ReadLine().Split(' '),e=>double.Parse(e));}
}