#include <iostream>
#include <algorithm>
#include <math.h>
#include <vector>
#include <set>
#include <queue>
#include <array>
#include <map>
#include <random>
#include <bitset>
#include <stack>
#include <deque>
#include <random>
#include <unordered_set>
#include <unordered_map>
#include <string>
#include <chrono>
//#include "towns.h"
using namespace std;
typedef long long ll;
typedef long double ld;
mt19937 gen(chrono::steady_clock::now().time_since_epoch().count());
int findSwapPairs(int N, int S[], int M, int X[], int Y[], int P[], int Q[]) {
for (int i = 0; i < M; ++i) {
bool fl = true;
for (int j = 0; j < N; ++j) {
fl = fl && (S[j] == j);
}
if (fl) return i;
swap(X[i], Y[i]);
P[i] = 0;
Q[i] = 0;
if (i % 2 == 0) continue;
for (int j = 0; j < N; ++j) {
if (S[j] != j) {
P[i] = j;
Q[i] = S[j];
swap(S[j], S[S[j]]);
break;
}
}
}
return M;
}
