#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;

int a, mx = 0;
vector <vector <int>> v(4);
vector <pair <int, int>> lep;
vector <pair <int, int>> ans1;
vector <pair <int, int>> ans2;

int hol(int x) {
    for (int& i : v[1]) if (i == x) return 1;
    for (int& i : v[2]) if (i == x) return 2;
    for (int& i : v[3]) if (i == x) return 3;
    return 0;
}

void hanoi(int x, int ra) {
    if (!x) return;
    int rol = hol(x);
    if (rol != ra) {
        hanoi(x - 1, 6 - rol - ra);
        v[rol].pop_back();
        v[ra].push_back(x);
        lep.push_back({ rol,ra });
    }
    hanoi(x - 1, ra);
}

int main()
{
    while (cin >> a && a) { v[1].push_back(a); mx++; }
    while (cin >> a && a) { v[2].push_back(a); mx++; }
    while (cin >> a && a) { v[3].push_back(a); mx++; }
    hanoi(mx, 1);
    ans1 = lep;

    for (int i = 1; i <= 3; i++) v[i].clear();
    lep.clear();
    while (cin >> a && a) v[1].push_back(a);
    while (cin >> a && a) v[2].push_back(a);
    while (cin >> a && a) v[3].push_back(a);
    hanoi(mx, 1);
    ans2 = lep;
    
    cout << ans1.size() + ans2.size() << endl;
    for (auto p : ans1) cout << p.first << " " << p.second << endl;
    reverse(ans2.begin(), ans2.end());
    for (auto p : ans2) cout << p.second << " " << p.first << endl;
}