#include <fstream>
#define nm 1000010

using namespace std;

ifstream fin("mins.in");
ofstream fout("mins.out");

int prim[nm],vect[nm],c,d,n;
long long z=0;

int main()
{
    int i,j;
    long long p;
    fin>>c>>d;
    fin.close();
    c--;d--;
    n=min(c,d);
    for(i=2;i<=n;i++)
    {
        if(!vect[i])
        {
        for(j=i;j<=n;j++)
        {
            vect[j]++;
        }
        p=1LL*i*i;
        for(j=p;j<=n;j+=p)
            prim[j]=1;
        }
        if(!prim[i])
        {
            if(!(vect[i]%2))
                z-=1LL*(c/i)*(d/i);
            else z+=1LL*(c/i)*(d/i);
        }
    }
    fout<<1LL*c*d-z;
    fout.close();
    return 0;
}