#include <iostream>
#include <algorithm>
#include <cstring>
#include <iomanip>
#include <fstream>
#include <cmath>
#include <vector>
#include <set>
#include <unordered_set>
#include <unordered_map>
#include <map>
#include <stack>
#include <queue>
#include <assert.h>
#include <limits>
#include <cstdio>
#include <complex>
#include "sorting.h"
#include <algorithm>
using namespace std;
const int MAXN = 200005;
int findSwapPairs(int n, int s[], int m, int x[], int y[], int p[], int q[]) {
int lo=0, hi=m;
while(lo<hi){
int mid=lo+(hi-lo)/2;
vector<int> fp(n), fpidx(n), sc(s, s+n);
for(int i=0;i<n;++i) fp[i]=i;
for(int i=0;i<mid;++i){
swap(fp[x[i]], fp[y[i]]);
}
for(int i=0;i<n;++i){
fpidx[fp[i]]=i;
}
vector<int> perm(n), idx(n);
for(int i=0;i<n;++i){
perm[i]=i;
idx[perm[i]]=i;
}
int j=0;
for(int i=0;i<mid;++i){
swap(sc[x[i]], sc[y[i]]);
swap(perm[x[i]], perm[y[i]]);
swap(idx[perm[x[i]]], idx[perm[y[i]]]);
bool found=false;
for(;j<n;j++){
int jj=idx[j];
if(fpidx[perm[jj]]!=sc[jj]){
found=true;
p[i]=jj;
q[i]=idx[fp[sc[jj]]];
swap(sc[p[i]], sc[q[i]]);
break;
}
}
if(!found) p[i]=q[i]=0;
}
bool ok=true;
for(int i=0;i<n;++i) if(sc[i]!=i) ok=false;
if(ok){
hi=mid;
}else{
lo=mid+1;
}
}
vector<int> fp(n), fpidx(n), sc(s, s+n);
for(int i=0;i<n;++i) fp[i]=i;
for(int i=0;i<lo;++i){
swap(fp[x[i]], fp[y[i]]);
}
for(int i=0;i<n;++i){
fpidx[fp[i]]=i;
}
vector<int> perm(n), idx(n);
for(int i=0;i<n;++i){
perm[i]=i;
idx[perm[i]]=i;
}
int j=0;
for(int i=0;i<lo;++i){
swap(sc[x[i]], sc[y[i]]);
swap(perm[x[i]], perm[y[i]]);
swap(idx[perm[x[i]]], idx[perm[y[i]]]);
for(;j<n;j++){
int jj=idx[j];
if(fpidx[perm[jj]]!=sc[jj]){
p[i]=jj;
q[i]=idx[fp[sc[jj]]];
swap(sc[p[i]], sc[q[i]]);
break;
}
}
}
return lo;
}
