#include <stdio.h>

int BFS(int person, int (*linked)[101], int N);

int main(){
    int linked[101][101] = {0,};
    int N,M;
    scanf("%d %d",&N, &M);
    for(int i=0; i<M; i++){
        int a, b;
        scanf("%d %d",&a, &b);
        linked[a][b] = 1;
        linked[b][a] = 1;
    }

    int min_kevin_bacon_num = 1000000;
    int result_person;

    for(int i=1; i<=N; i++){
        int current_kevin_bacon_num = BFS(i, linked, N);
        if(current_kevin_bacon_num < min_kevin_bacon_num) {
            min_kevin_bacon_num = current_kevin_bacon_num;
            result_person = i;
        }
    }

    printf("%d\n",result_person);

    return 0;
}

int BFS(int person, int (*linked)[101], int N){
    int front = 0, rear = 0;
    int queue[101];

    int distance[101] = {0,};

    queue[rear++] = person;
    distance[person] = 1;

    while(front<rear){
        int current_person = queue[front++];
        for(int i=1; i<=N; i++){
            if(linked[current_person][i] == 1 && distance[i] == 0){
                distance[i] = distance[current_person] + 1;
                queue[rear++] = i;
            }
        }
    }

    int total_distance = 0;
    for(int i=1; i<=N; i++){
        total_distance += (distance[i] - 1);
    }

    return total_distance;
}