#include <iostream>
#include <vector>
#include <numeric>
using namespace std;
using pii = pair<int,int>;
template <class T>
bool chmax (T &a, T b) {
if (a < b) {
a = b;
return true;
}
return false;
}
int main() {
ios::sync_with_stdio(false);
int n;
cin >> n;
vector <int> cnt(2 * n);
vector <pair <int, int>> a(n);
vector <int> who(2 * n);
for (int i = 0; i < n; ++i) {
int u, v;
cin >> u >> v;
if (u > v) {
swap(u, v);
}
a[i] = {u, v};
who[u] = who[v] = i;
cnt[(u + v) % (2 * n)]++;
}
int res = 0;
int j = -1;
for (int i = 1; i < 2 * n; i += 2) {
if (chmax(res, cnt[i])) {
j = i;
}
}
cout << n - res << '\n';
for (int i = 0; i < n; ++i) {
int cur = i;
while (true) {
if ((a[cur].first + a[cur].second) % (2 * n) == j) {
break;
}
int k = (j + 2 * n - a[cur].first) % (2 * n);
cout << cur << ' ' << a[cur].second << ' ' << k << '\n';
a[cur].second = k;
int to = who[k];
if (a[to].first == k) {
swap(a[to].first, a[to].second);
}
cur = to;
}
}
return 0;
}
