#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()
/*
static char _buffer[1024];
static int _currentChar = 0;
static int _charsNumber = 0;
static FILE *_inputFile, *_outputFile;
static inline int _read() {
if (_charsNumber < 0) {
exit(1);
}
if (!_charsNumber || _currentChar == _charsNumber) {
_charsNumber = (int)fread(_buffer, sizeof(_buffer[0]), sizeof(_buffer), _inputFile);
_currentChar = 0;
}
if (_charsNumber <= 0) {
return -1;
}
return _buffer[_currentChar++];
}*/
int findSwapPairs(int n, int S[], int M, int X[], int Y[], int P[], int Q[]){
vl arr(n);
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){
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);
swap(arr[i], arr[aux]);
}
ff(i, 0, a.size()){
P[i] = a[i];
Q[i] = b[i];
}
return c;
}
/*
static inline int _readInt() {
int c, x, s;
c = _read();
while (c <= 32) c = _read();
x = 0;
s = 1;
if (c == '-') {
s = -1;
c = _read();
}
while (c > 32) {
x *= 10;
x += c - '0';
c = _read();
}
if (s < 0) x = -x;
return x;
}
int main()
{
int N, M;
N = _readInt();
int *S = (int*)malloc(sizeof(int) * (unsigned int)N);
for (int i = 0; i < N; ++i)
S[i] = _readInt();
M = _readInt();
int *X = (int*)malloc(sizeof(int) * (unsigned int)M), *Y = (int*)malloc(sizeof(int) * (unsigned int)M);
for (int i = 0; i < M; ++i) {
X[i] = _readInt();
Y[i] = _readInt();
}
int *P = (int*)malloc(sizeof(int) * (unsigned int)M), *Q = (int*)malloc(sizeof(int) * (unsigned int)M);
int ans = findSwapPairs(N, S, M, X, Y, P, Q);
fprintf(_outputFile, "%d\n", ans);
for (int i = 0; i < ans; ++i)
fprintf(_outputFile, "%d %d\n", P[i], Q[i]);
return 0;
}
*/
