#include <algorithm>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <ctime>
#include <iostream>
#include <sstream>
#include <functional>
#include <map>
#include <string>
#include <cstring>
#include <vector>
#include <queue>
#include <stack>
#include <deque>
#include <set>
#include <list>
#include <numeric>
using namespace std;
const double PI = 3.14159265358979323846;
const double EPS = 1e-12;
const int INF = 1<<25;
typedef pair<int,int> P;
typedef long long ll;
typedef unsigned long long ull;
#define T 12000000
#define R 33000
#define N 200

int n, m, r[N], s[N], s2[N], s3[N], t[R][N], a[N], tmp[N], rr[20], ccnt;
vector<int> t2[R];
set<vector<int> > st;

void ap(int *a, int *b){
	memcpy(tmp, a, sizeof(tmp));
	for(int i = 0; i < n; i++)
		a[i] = tmp[b[i]];
}

int lcm(int a, int b){
	return a/__gcd(a, b)*b;
}

int main(){
	srand(time(NULL));
	cin>>n>>m;
	int rnd1 = rand()%n, rnd2 = rand()%n;
	for(int i = 0; i < n; i++) r[i] = i;
	memcpy(s, r, sizeof(s));
	memcpy(s2, r, sizeof(s));
	memcpy(s3, r, sizeof(s));
	for(int i = 0; i < m; i++){
		int x, y;
		cin>>x>>y;
		swap(s[x-1], s[x]);
	}
	ll E = 1;
	for(int i = 0; i < n; i++){
		int cnt = 1, p = s[i];
		bool small = true;
		while(p!=i){
			if(p>i) small = false;
			p = s[p];
			cnt++;
		}
		if(small){
			rr[ccnt++] = i;
		}
		E = lcm(E, cnt);
	}
	cout<<E<<endl;
	return 0;
}