A,B=map(int,input().split())
A,B=min(A,B),max(A,B)
if B%A==0:
  print(A)
else:
  def gcd(a,b):
    a,b=max(a,b),min(a,b)
    if a%b==0:
      return b
    while b%a!=0:
      return gcd(b,a%b)
  print(gcd(gcd(A+B,A),gcd(A+B,B)))