#include <iostream>
#include <fstream>
#include <cstring>

using namespace std;

ifstream f("mins.in");
ofstream g("mins.out");

long long int n,m,nr[1000005],ciur[1000005],minim,maxim,cap,trap;
long long sum,aux;

int main()
{
f>>n>>m;
n--; m--;
minim=min(n,m); maxim=max(n,m);
for(int i=2;i<=minim;i++)
 ciur[i]=1;
sum+=(maxim-1)*(maxim)/2-(maxim-minim)*(maxim-minim+1)/2;
sum+=(minim-2)*(minim-1)/2;
sum+=n+m-1;
for(int i=2;i<=minim;i++)
 {
  if(ciur[i]==1)
    for(int j=i;j<=minim;j+=i)
     {
      ciur[j]*=i;
      nr[j]++;
     }
  if(ciur[i]==i)
   {
    cap=minim/i; trap=maxim/i;
    cap=trap-cap;
    if(nr[i]%2==1)
    {
    sum-=(maxim/i)*(maxim/i+1)/2-cap*(cap+1)/2;
    sum-=(minim/i-1)*(minim/i)/2;
    }
    else
    {
    sum+=(maxim/i)*(maxim/i+1)/2-cap*(cap+1)/2;
    sum+=(minim/i-1)*(minim/i)/2;
    }
   }
 }
for(int i=2;i<=minim;i++)
  {ciur[i]=1; nr[i]=0;}
g<<sum;
}