#include <iostream>
#include <fstream>
#define MAX 1000005
using namespace std;
ifstream f("mins.in");
ofstream g("mins.out");
int n,m,k,a[MAX],b[MAX]; long long sol;
void read() { f>>n>>m; --n; --m; k=min(n,m); }
void solve()
{
    int i,j; sol=1LL*n*m;
    for(i=2;i<=k;i++)
    {
        if(!a[i])
        {
            for(j=i;j<=n;j+=i)++a[j];
            if(1LL*i*i<=1LL*n)for(j=i*i;j<=n;j+=i*i)b[j]=1;
        }
        if(!b[i])if(a[i]%2)sol-=1LL*(1LL*n/i)*(1LL*m/i); else sol+=1LL*(1LL*n/i)*(1LL*m/i);
    }
    g<<sol;
}
int main()
{
    read();solve();
    return 0;
}