#include<cstdio>
long a[1000][1000],gr[1000],ok,n,m,i,j,x,y;
void euler(long k){
	long i;
	for(i=1;i<=n;i++)
		if(a[k][i]>0){
			a[k][i]=0;a[i][k]=0;
			euler(i);
		}
	printf("%ld ",k);
}
int main(){
	freopen("in.txt","r",stdin);
	freopen("out.txt","w",stdout);
	scanf("%ld%ld",&n,&m);
	for(i=0;i<m;i++){
		scanf("%ld%ld",&x,&y);
		gr[x]++;gr[y]++;
		a[x][y]=1;a[y][x]=1;
	}
	ok=0;
	for(i=1;i<=n;i++)
		if(gr[i]%2==1)ok=1;
	if(ok==1)printf("nu admite ciclu eulerian\n");
	else
		euler(1),printf("\n");
	fclose(stdin);
	fclose(stdout);
	return 0;
}