from fractions import gcd
N=input();K=input();A=range(N)
for i in xrange(K):
	x,y=map(int,raw_input().split())
	A[x-1],A[x]=A[x],A[x-1]
mv={A[i]:i for i in xrange(N)}
ans=1
for i in xrange(N):
	h=mv[i];cnt=1
	while h!=i:cnt+=1;h=mv[h]
	ans=ans*cnt/gcd(ans,cnt)
print ans