#include "sorting.h"
#include<bits/stdc++.h>
using namespace std;
#define mp make_pair
#define pb push_back
typedef pair<int,int> ii;
int findSwapPairs(int N, int S[], int M, int X[], int Y[], int P[], int Q[]) {
int l = 0 , h = M;
auto check = [&](int mid){
vector<int> cur(N , 0) , pos(N , 0);
for(int i = 0 ; i < N ; ++i)cur[i] = S[i] , pos[cur[i]] = i;
for(int i = 0 ; i < mid ; ++i){
swap(pos[cur[X[i]]] , pos[cur[Y[i]]]);
swap(cur[X[i]] , cur[Y[i]]);
}
vector<ii> ans;
for(int i = 0 ; i < N ; ++i){
if(cur[i] != i){
ans.pb(mp(i , cur[i]));
int tmp = pos[i];
swap(pos[i] , pos[cur[i]]);
swap(cur[i] , cur[tmp]);
assert(cur[i] == i);
assert(pos[i] == i);
}
}
for(int i = 0 ; i < N ; ++i)cur[i] = S[i] , pos[cur[i]] = i;
for(int i = 0 ; i < mid ; ++i){
P[i] = Q[i] = 0;
assert(pos[cur[X[i]]] == X[i]);
assert(pos[cur[Y[i]]] == Y[i]);
swap(pos[cur[X[i]]] , pos[cur[Y[i]]]);
swap(cur[X[i]] , cur[Y[i]]);
if(i < ans.size()){
P[i] = pos[ans[i].first];
Q[i] = pos[ans[i].second];
swap(cur[P[i]] , cur[Q[i]]);
swap(pos[ans[i].first] , pos[ans[i].second]);
}
}
return ans.size() <= mid;
};
while(l <= h){
int mid = l + h >> 1;
if(check(mid))h = mid - 1;
else l = mid + 1;
// cout << mid << endl;
// for(int i = 0 ; i < N ; ++i)cout << cur[i] << " ";
// cout << endl;
}
check(l);
return l;
}
#ifdef LOCAL
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "sorting.h"
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++];
}
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()
{
_inputFile = fopen("sorting.in", "rb");
_outputFile = fopen("sorting.out", "w");
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;
}
#endif // LOCAL
