#include<iostream>
using namespace std;
int main () {
    int N,M;
    cin>>N>>M;
		N--;
		M--;
    int x=1,y=1,myX=0,myY=0,result=1,Px,Py;
    while(true) {
        Px=myX;
        Py=myY;
        myX+=x;
        myY+=y;
        if((myX==0 and myY==0) or (myX==0 and myY==M) or (myX==N and myY==0) or (myX==N and myY==M)) {
            break;
        }
        //myX==0
        if(myX==0 and Px>myX and Py>myY) {
            result++;
            x=1;
            y=-1;
        }
        if(myX==0 and Px>myX and Py<myY) {
            result++;
            x=1;
            y=1;
        }
        //myX==N
        if(myX==N and Px<myX and Py<myY) {
            result++;
            x=-1;
            y=1;
        }
        if(myX==N and Px<myX and Py>myY) {
            result++;
            x=-1;
            y=-1;
        }
        //myY==0
        if(myY==0 and Px<myX and Py>myY) {
            result++;
            x=1;
            y=1;
        }
        if(myY==0 and Px>myX and Py>myY) {
            result++;
            x=-1;
            y=1;
        }
        //myY==M
        if(myY==M and Px<myX and Py<myY) {
            result++;
            x=1;
            y=-1;
        }
        if(myY==M and Px>myX and Py<myY) {
            result++;
            x=-1;
            y=-1;
        }
    }
    cout<<result;
    return 0;
}
