#include <iostream>
#include <fstream>
#include <algorithm>

using namespace std;

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

const int maxN = 5005;
int n, p[maxN][3], ans, aib[maxN], v[maxN];

void update(int poz, int val)
{
    for(int i = poz; i <= n; i += (i & (-i)))
        aib[i] += val;
}

void place(int poz, int val)
{
    int aux = 0, auxp = 0;
    for(int i = (1 << 20); i; i >>= 1)
        if(aux + i <= n && auxp + aib[aux + i] < poz)
            auxp += aib[aux + i], aux += i;
    aux++;
    v[aux] = val;
    update(aux, -1);
    return;
}

void solve(int val, int len)
{
    if(len == 0)
        return;
    ans++;
    if(len == 1)
    {
        place(1, 1);
        return;
    }
    if(p[len][0] == p[len][1] || p[len][1] == p[len][2])
    {
        place(p[len][1], val);
        solve(val - 1, len - 1);
    }
    else
    {
        place(p[len][2], val);
        place(p[len][1], val - 1);
        solve(val - 2, len - 2);
    }
}

int main()
{
    fin >> n;
    update(1, 1);
    for(int i = 2; i <= n; i++)
    {
        for(int j = 0; j < 3; j++)
            fin >> p[i][j];
        sort(p[i], p[i] + 3);
        update(i, 1);
    }
    solve(n, n);
    fout << ans << '\n';
    for(int i = 1; i <= n; i++)
        fout << v[i] << ' ';
    return 0;
}