// Danh sach ke
#include <bits/stdc++.h>
 
using namespace std;
const int nmax = 10000;
 
vector <int> g[nmax];
 
int main()
{
    freopen("task.inp", "r", stdin);
    freopen("task.out", "w", stdout);
    int n, m;
    cin >> n >> m;
    for(int i = 1; i <= m; ++i) {
        int u, v; cin >> u >> v;
        g[u].push_back(v);
        g[v].push_back(u);
    }
    for(int i = 1; i <= n; ++i) {
        cout << i << ": ";
        for(int j = 0; j < g[i].size(); ++j) {
            cout << g[i][j] << " ";
        }
        cout << endl;
    }
 
    return 0;
}
 

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