/* -*- coding: utf-8 -*-
 *
 * 101.cc: No.101 ぐるぐる!あみだくじ! - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int MAX_N = 100;

/* typedef */

typedef vector<int> vi;

/* global variables */

/* subroutines */

void print_v(vi &v) {
  for (int i = 0; i < v.size(); i++) printf("%d ", v[i]); putchar('\n');
}

/* main */

int main() {
  int n, k;
  cin >> n >> k;

  vi gv(n);
  for (int i = 0; i < n; i++) gv[i] = i;
  vi sv(gv), v(gv);

  for (int i = 0; i < k; i++) {
    int x, y;
    cin >> x >> y;
    x--, y--;
    swap(v[x], v[y]);
  }
  //print_v(v);

  int cnt = 0;
  do {
    cnt++;
    vi tv(n);
    for (int i = 0; i < n; i++) tv[i] = sv[v[i]];
    swap(sv, tv);
  } while (sv != gv);

  printf("%d\n", cnt);
  return 0;
}