#include <iostream>
#include <cmath>
#include <vector>
#include <utility>
#include <queue>
#include <map>
#include <string>
#include <cstring>
#include <list>
#include <algorithm>
#define INF 114514

using namespace std;

typedef pair<double,double> P;

bool check(vector<int> &a){
	for(int i=0;i<a.size();i++){
		if(a[i] != i)return false;
	}
	return true;
}

int main(void){
	int n,k;
	cin >> n >> k;
	vector<int> x(n),y(n);
	for(int i=0;i<k;i++){
		cin >> x[i] >> y[i];
		x[i]--;y[i]--;
	}

	vector<int> a(n),b(n);
	map<int,int> fx;
	for(int i=0;i<n;i++)a[i] = i;
	for(int i=0;i<k;i++)swap(a[x[i]],a[y[i]]);
	for(int i=0;i<n;i++)fx[i] = a[i];
	b = a;

	int cnt = 1;
	while(!check(a)){
		b = a;
		for(int i=0;i<n;i++)a[i] = b[fx[i]];
		cnt++;
	}
	cout << cnt << endl;



	return 0;
}