#include <bits/stdc++.h>
using namespace std;
int main(){
ios::sync_with_stdio(false);
cin.tie(nullptr);
int N;
cin >> N;
int M = 2*N;
vector<pair<int,int>> s(N);
vector<int> who(M);
for(int i=0;i<N;i++){
cin >> s[i].first >> s[i].second;
who[s[i].first] = i;
who[s[i].second] = i;
}
vector<tuple<int,int,int>> moves;
for(int i=0;i<M;i+=2){
int p1 = i;
int p2 = i+1;
int s1 = who[p1];
int s2 = who[p2];
if(s1 == s2) continue;
// mover extremo de s1 hacia p2
if(s[s1].first == p1){
moves.push_back({s1, s[s1].second, p2});
who[s[s1].second] = s2;
s[s1].second = p2;
} else {
moves.push_back({s1, s[s1].first, p2});
who[s[s1].first] = s2;
s[s1].first = p2;
}
}
cout << moves.size() << "\n";
for(auto &t : moves){
int p,s,e;
tie(p,s,e) = t;
cout << p << " " << s << " " << e << "\n";
}
return 0;
}
