#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
#define ff first
#define ss second
#define pb push_back
#define all(a) (a).begin(), (a).end()
#define replr(i, a, b) for (int i = int(a); i <= int(b); ++i)
#define reprl(i, a, b) for (int i = int(a); i >= int(b); --i)
#define rep(i, n) for (int i = 0; i < int(n); ++i)
#define mkp(a, b) make_pair(a, b)
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> PII;
typedef vector<int> VI;
typedef vector<PII> VPI;
typedef vector<VI> VVI;
typedef vector<VVI> VVVI;
typedef vector<VPI> VVPI;
typedef pair<ll, ll> PLL;
typedef vector<ll> VL;
typedef vector<PLL> VPL;
typedef vector<VL> VVL;
typedef vector<VVL> VVVL;
typedef vector<VPL> VVPL;
template<class T> T setmax(T& a, T b) {if (a < b) return a = b; return a;}
template<class T> T setmin(T& a, T b) {if (a < b) return a; return a = b;}
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
template<typename T>
using indset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#include "sorting.h"
#define ANSWER {\
rep(i, ans.size()) {\
P[i] = ans[i].ff;\
Q[i] = ans[i].ss;\
}\
return ans.size();\
}
struct PERM {
int n;
VI a;
VI ind;
PERM(int N_ARG) : n(N_ARG) {
a = ind = VI(n);
rep(i, n) a[i] = ind[i] = i;
}
PERM(VI A_ARG) : a(A_ARG) {
n = a.size();
ind = VI(n);
rep(i, n) ind[a[i]] = i;
}
int size() {
return n;
}
int& operator[](const int i) {
return a[i];
}
};
PERM operator*(const PERM& perm, const PII p) {
auto[x, y] = p;
PERM ret = perm;
swap(ret.ind[ret[x]], ret.ind[ret[y]]);
swap(ret[x], ret[y]);
return ret;
}
void operator*=(PERM& perm, const PII p) {
perm = perm * p;
}
VPI ret;
bool f(const VI& A_ARG, const VPI& op) {
PERM a(A_ARG);
int n = a.size();
int m = op.size();
PERM cur(n);
reprl(i, m-1, 0) cur *= op[i];
int i = 0;
for (const PII& p : op) {
cur *= p;
a *= p;
while (i < n && a.ind[i] == cur.ind[i]) i++;
int x, y;
if (i == n) {
x = y = 0;
} else {
x = a.ind[i];
y = cur.ind[i];
}
ret.pb({x, y});
a *= mkp(x, y);
}
rep(i, n) if (a[i] != i) return false;
return true;
}
int findSwapPairs(int N, int S[], int M, int X[], int Y[], int P[], int Q[]) {
int n = N;
int m = M;
VI a(n);
rep(i, n) a[i] = S[i];
VPI op(m);
rep(i, M) op[i] = mkp(X[i], Y[i]);
VPI ans(m+1);
VPI curop;
rep(i, m+1) {
/*cout << "KPORDZENQ " << i << " HATOV" << endl;*/
ret.clear();
if (f(a, curop)) {
if (ret.size() < ans.size()) {
ans = ret;
/*cout << "AVELI LAV PATASXAN GTAV" << endl;*/
/*rep(i, ans.size()) {*/
/* cout << ans[i].ff << " " << ans[i].ss << endl;*/
/*}*/
}
}
if (i == m) break;
curop.pb(op[i]);
}
ANSWER;
}
