#include <bits/stdc++.h>
#define pb push_back
#define fi first
#define se second
#define ll long long int
#define all(v) (v).begin(),(v).end()
using namespace std;
int main() {
int n; cin >> n;
vector<pair<int,int>> v(n); // string to pins
vector<int> m(2*n), p(2*n), p2p(2*n); // p = pin to string, p2p = pin to pin
vector<bool> vis(n);
int tgt = 1; int cur = 0;
for (int i = 0; i < n; i++) {
cin >> v[i].fi >> v[i].se;
int sum = v[i].fi + v[i].se;
sum %= 2*n; m[sum]++;
p[v[i].fi] = i; p[v[i].se] = i;
p2p[v[i].fi] = v[i].se;
p2p[v[i].se] = v[i].fi;
}
for (int i = 1; i < 2*n; i += 2) {
if (cur < m[i]) {
cur = m[i]; tgt = i;
}
}
int cnt = 0;
for (int i = 0; i < n; i++) {
int sum = v[i].fi + v[i].se;
sum %= 2*n;
if (sum == tgt) {vis[i] = 1; continue;}
cnt++;
}
cout << cnt << "\n";
for (int i = 0; i < n; i++) {
if (vis[i]) continue;
int cur = tgt - v[i].fi; cur %= 2*n;
if (cur < 0) cur += 2*n;
cout << i << " " << v[i].se << " " << cur << "\n";
while (cur != v[i].se) {
int pn = tgt - p2p[cur]; pn %= 2*n;
if (pn < 0) pn += 2*n;
cout << p[cur] << " " << cur << " " << pn << "\n";
vis[p[cur]] = 1; swap(pn, cur);
}
}
return 0;
}
