#include<stdio.h>
int cmmdc (int x, int y)
{
    int r;
    while(y)
        {
            r=x%y;
            x=y;
            y=r;
        }
    return x;
}

int main()
{
    freopen("mins.in","r",stdin);
    freopen("mins.out","w",stdout);
    int nrp,res,c,d,i,j;
    scanf("%d%d",&c,&d);
    nrp=0;
    for(i=1;i<c;i++)
        nrp=nrp+cmmdc(i,d-1);
    for(j=1;j<d-1;j++)
        nrp=nrp+cmmdc(j,c-1);
    res=c-1+d-2+(c-1)*(d-1)-nrp;
    printf("%d\n",res);
    return 0;
}