#include <cstdio>
#include <bitset>

#define XMax 1000005
#define LL long long

using namespace std;

bitset <XMax> V, Not;
int F[XMax], A, B;
LL S;

void Eratosthenes ()
{
    for (int i=2; i<XMax; ++i)
    {
        if (!F[i])
        {
            F[i]=1;
            for (int j=i+i; j<XMax; ++j)
            {
                ++F[j];
            }
            if (1LL*i*i>=XMax) continue;
            for (int j=i*i; j<XMax; j+=(i*i))
            {
                Not[j]=1;
            }
        }
    }
}

void Pinex ()
{
    S=1LL*A*B;
    for (int X=2; X<XMax; ++X)
    {
        if (Not[X]) continue;
        int Sign=-1;
        if (F[X]%2) Sign=1;
        S-=(1LL*Sign*(A/X)*(B/X));
    }
}

void Solve ()
{
    Eratosthenes ();
    Pinex ();
}

void Read ()
{
    freopen ("mins.in", "r", stdin);
    scanf ("%lld %lld", &A, &B);
    --A, --B;
}

void Print ()
{
    freopen ("mins.out", "w", stdout);
    printf ("%lld\n", S);
}

int main()
{
    Read ();
    Solve ();
    Print ();
    return 0;
}