#include <stdio.h>

int ans[105]; int max = 0;
int n, k;
int black[105];    int pos = 0;
char colorNode[105];
char adjacent[105][105];

void color(void)
{
    int i, j;
    int flag;
    if( pos > max ) {
        max = pos;
        for( i = 0 ; i < max ; i++ )
            ans[i] = black[i];
    }
    for(i = 1 ; i <= n ; i++) {      /* trying to color this black */
        if( colorNode[i] == 1 )    /* already black */
            continue;
        flag = 1;
        for( j = 1 ; j <= n ; j++ ) {
            if( j == i )
                continue;
            if( colorNode[j] == 1 && adjacent[i][j] == 1 ) {
                flag = 0;
                break;
            }
        }
        if( flag ) {
            colorNode[i] = 1;
            black[pos++] = i;
            color();
            pos--;
            colorNode[i] = 0;
        }
    }
}

int main()
{
    int i, t1, t2;

    scanf("%d %d", &n, &k);

    for(i = 0 ; i < k ; i++) {
        scanf("%d %d", &t1, &t2);
        adjacent[t1][t2] = adjacent[t2][t1] = 1;
    }

    color();

    printf("%d\n", max);
    for(i = 0 ; i < max ; i++) 
        printf("%d ", ans[i]);

    return 0;
}