#include<cstdio>
#include<cstring>
#include<algorithm>
#define Nmax 1000005
using namespace std;
int n,i,j,c,d,v[Nmax];
bool w[Nmax];
long long sol;
int main()
{
    freopen("mins.in","r",stdin);
    freopen("mins.out","w",stdout);
    scanf("%d %d",&c,&d);
    --c; --d;
    sol=c*d*1LL;
    n=min(c,d);
    for (i=2;i<=n;i++)
    if (!v[i])
    {
        for (j=i;j<=n;j+=i) ++v[j];
        if (i*i>n || i*i<0) continue;
        for (j=i*j;j<=n;j+=i) w[j]=1;
    }
    for (i=2;i<=n;i++)
    if (!w[i] && v[i]%2==1)
    sol=sol-((c/i)*(d/i));
    else if (!w[i]) sol=sol+((c/i)*(d/i));
    printf("%lld",sol);
    return 0;
}