def gcd(a,b):
    if b< a:
        return gcd(b,a)
    if b%a==0:
        return a
    return gcd(b%a,a)

N=int(raw_input())
K=int(raw_input())
a=[i+1 for i in range(N)]
for i in range(K):
    x,y=map(int,raw_input().split())
    a[x-1],a[y-1]=a[y-1],a[x-1]

ans = 1
for i in range(len(a)):
    if a[i]!=-1 and a[i]!=i+1:
        cnt=1
        cur=i
        while a[cur]!=i+1:
            cnt+=1
            tmp=cur
            cur=a[cur]-1
            a[tmp]=-1
        a[cur]=-1
        g= gcd(ans,cnt)
        ans*=cnt/g

print ans