#include<fstream>
#include<algorithm>
#define inf -1000100
using namespace std;
ifstream f("mins.in");
ofstream g("mins.out");
long long v[1000100];
long long a,i,j,n,m,c,d,S;
int main ()
{
	f>>c>>d;
	c--;
	d--;
	n=min(c,d);
	m=max(c,d);
	S=n*m;
	for(i=2;i<=n;++i)
		if(!v[i])
		{
			a=m/i;
			S-=(n/i)*a;
			for(j=i;j<=n;j+=i)
				v[j]++;
			a=i*i;
			for(j=a;j<=n;j+=a)
			{
				v[j]=inf;
			}
		}
		else
		if(v[i]>1)
		{
			a=m/i;
			if(v[i]%2)
				S-=(n/i)*a;
			else
				S+=(n/i)*a;
		}
	g<<S;
	return 0;
}