#include <fstream>
#define DIM 1000001
using namespace std;
ifstream fin("mins.in");
ofstream fout("mins.out");
long long x,y,mini,nr,sol;
int nrd[DIM];
bool c[DIM],f[DIM];
int main() {
    fin>>x>>y;
    x--;
    y--;
    mini=min(x,y);
    for (int i=2;i<=mini;i++) {
        if (c[i]==0) {
            for (int j=2*i;j<=mini;j+=i) {
                c[j]=1;
                nrd[j]++;
                if (j%(i*i)==0)
                    f[j]=1;
            }
            nrd[i]=1;
        }
        if (f[i]==0) {
            nr=(x/i)*(y/i);
            if (nrd[i]%2==0)
                sol-=nr;
            else
                sol+=nr;
        }
    }
    fout<<x*y-sol;
    return 0;
}