#include <bits/stdc++.h>
//#include "sorting.h"
using namespace std;
#define ll long long
#define vb vector<bool>
#define pb push_back
#define ff(aa, bb, cc) for(ll aa = bb; aa < cc; aa++)
#define vl vector<ll>
#define pll pair<ll, ll>
#define fi first
#define se second
#define ed "\n"
#define all(aaa) aaa.begin(), aaa.end()
#define rall(aaa) aaa.rbegin(), aaa.rend()
int findSwapPairs(int n, int S[], int M, int X[], int Y[], int P[], int Q[]) {
vl arr;
ff(i, 0, n){
arr.pb(S[i]);
}
map<ll, vl> mp;
vl sorted = arr;
sort(all(sorted));
map<ll, vl> fin;
ff(i, 0, n){
if(arr[i] != sorted[i]){
fin[sorted[i]].pb(i);
}
}
ff(i, 0, n){
if(arr[i] != sorted[i]){
mp[arr[i]].pb(i);
}
}
ll c = 0;
vl a, b;
ff(i, 0, n){
//cout << arr[i] << " " << sorted[i] << ed;
if(arr[i] == sorted[i]){
continue;
}
c++;
ll sup = sorted[i];
ll aux = 0;
/*ff(id, 0, n){
cout << arr[id] << " ";
}
cout << ed;
cout << arr[i] << " " << sorted[i] << ed;*/
for(auto &p : mp[sup]){
aux = p;
if(sorted[p] == arr[i]){
break;
}
}
//cout << "P " << i << " " << aux << ed;
for(auto &p : mp[arr[i]]){
//cout << p << " ";
if(p == i){
p = aux;
break;
}
}
//cout << ed;
for(auto &p : mp[arr[aux]]){
//cout << p << " ";
if(p == aux){
p = i;
}
}
//cout << ed << ed;
a.pb(i);
b.pb(aux);
//cout << i << " " << aux << ed;
swap(arr[i], arr[aux]);
}
ff(i, 0, a.size()){
P[i] = a[i];
Q[i] = b[i];
}
return c;
}
/*
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
int N, M;
cin >> N;
vector<int> S(N);
ff(i, 0, N) cin >> S[i];
cin >> M;
vector<int> X(M), Y(M);
ff(i, 0, M) cin >> X[i] >> Y[i];
vector<int> P, Q;
int ans = findSwapPairs(N, S, M, X, Y, P, Q);
cout << ans << ed;
ff(i, 0, ans) {
cout << P[i] << " " << Q[i] << ed;
}
return 0;
}
*/
