#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define int long long
#define maxn 500005
#define mi LLONG_MIN
#define ma LLONG_MAX
#define mod 1000000007
#define pb push_back
#define S second
#define F first
struct st {
int c, x, y;
};
void solve() {
int n;
cin >> n;
vector<pair<int, int>> a(n * 2);
vector<pair<int, int>> b(n);
for (int i = 0; i < n; i++) {
int l, r;
cin >> l >> r;
a[l] = {i, r};
a[r] = {i, l};
b[i] = {l, r};
}
cout << n - 2 + (n % 2) << "\n";
for (int i = 1; i < n; i++) {
if (i * 2 + 1 != n * 2 + 2 - (i * 2 + 1))
cout << i << " " << i * 2 + 1 << " " << n * 2 + 2 - (i * 2 + 1)
<< "\n";
}
/*
int ans = ma;
vector<st> vec;
cout << ans << "\n";
for (auto [p, s, e] : vec) {
cout << p << " " << s << " " << e << "\n";
}
*/
}
int32_t main() {
ios::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
int t = 1;
// cin >> t;
while (t--) solve();
}
