using namespace std;
int main()
{
  int a,b,c,a1,b1,c1,x=2;
  cin>>a>>b>>c;
  while(1)
  {a1=a%x;  b1=b%x;  c1=c%x;  
   if(a1==b1&&a1==c1){cout<<x;break;}
   x++;
  }
  return 0;
}