def g;gets.split.map(&:to_i)end
l=[*0..n=g[0]]
g[0].times{
  a,b=g
  l[a],l[b]=l[b],l[a]
}
cnt=1
now=l.dup
until now==[*0..n]
  now.map!{|i|l[i]}
  cnt+=1
end
p cnt