1389

import java.util.*;
 
class pair{
	int x,d;
	
	public pair(int x, int depth) {
		this.x = x;
		this.d = depth;
	}
}

public class Main {
	
	public static int[][] rel;
	public static int[] checked;
	public static int N,M;
	public static int min=Integer.MAX_VALUE;
	public static int mp;
	
    public static void main(String[] args) {
    
    	Scanner sc = new Scanner(System.in);
    	
    	N = sc.nextInt();	// 유저의 수
    	M = sc.nextInt();	// 관계의 수
    	
    	rel = new int[N+1][N+1];
    	checked = new int[N+1];
    	
    	for(int i=0; i<M; i++) {
    		int x = sc.nextInt();
    		int y = sc.nextInt();
    		rel[x][y] = rel[y][x] = 1;
    	}
    	
    	//체크
    	for(int i=1; i<N+1; i++) {
    		if(min>findkb(i)) {
    			min = findkb(i);
    			mp = i;
    		}
    	}
    	System.out.println(mp);
    	
    	sc.close();
    }
		
    public static int findkb(int a) {
    	Queue <pair> q = new LinkedList<pair>(); 
    	int sum = 0;
    	
    	for(int i=1;i<N+1; i++)
    		checked[i]=0;
    	checked[a] = 1;
    	q.add(new pair(a,1));
    	
    	while(!q.isEmpty()) {
    		pair n = q.poll();
    		
    		
    		for(int i=1; i<N+1; i++) {
    			if(rel[n.x][i]==1 && checked[i]!=1) {
    				checked[i] = 1;
    				q.add(new pair(i,n.d+1));
    				sum += n.d;
    				//체크
//    				System.out.println(n.x+"과"+i+"확인" + n.d);
    			}
    		}
    	}
    	
    	
    	return sum; 
    }
    
}