#include <bits/stdc++.h>

using namespace std;
ifstream fin("sortare.in");
ofstream fout("sortare.out");

inline int nth_pos(int n, vector <int> &v){
    int ans = 0;
    for(int i = 0; i < n; i++){
        ans++;
        while(v[ans] != 0)
            ans++;
    }
    return ans;
}

int main()
{
    int n;
    fin >> n;
    int l = n, ans = 1, mx = n;
    vector <vector <int>> op(n + 1, vector <int> (3));
    vector <int> v(n + 1);
    for(int i = 2; i <= n; i++){
        for(int j = 0; j < 3; j++)
            fin >> op[i][j];
        sort(op[i].begin(), op[i].end());
    }
    while(l > 1){
        if(op[l][0] == op[l][1] || op[l][1] == op[l][2]){
            v[nth_pos(op[l][1], v)] = mx--;
            l--;
        }
        else{
            v[nth_pos(op[l][2], v)] = mx--;
            v[nth_pos(op[l][1], v)] = mx--;
            l -= 2;
        }
        ans++;
    }
    fout << ans << '\n';
    for(int i = 1; i <= n; i++){
        if(v[i] == 0)
            fout << mx-- << ' ';
        else
            fout << v[i] << ' ';
    }
    fin.close();
    fout.close();
    return 0;
}