#include <bits/stdc++.h>
using namespace std;
int main(){

    int n,m;
    scanf("%d %d",&n,&m);
    vector <int> v[n+1];
    for(int i=1;i<=m;i++){
        int x,y;
        scanf("%d %d",&x,&y);
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(int i=1;i<=n;i++){
        printf("%d | ",i);
        sort(v[i].begin(),v[i].end());
        for(int j=0;j<v[i].size();j++){
            printf("%d ",v[i][j]);
        }
        printf("\n");
    }

    return 0;
}