C++ :

#include<iostream>
#include<algorithm>
using namespace std;


int gcd(int a,int b)
{
    if(b==0) return a;
    if(a==0) return b;
    else return gcd(b%a,a);

    }

int main()
{
    int n,m,h,w,ans;

    while(cin>>n>>m)
    {


       if(n==1||m==1)
        cout<<max(n,m)<<endl;
       else
       {
        cout<<gcd(n-1,m-1)+1<<endl;
       }
    }
    return 0;
}