#include <bits/stdc++.h>
#pragma GCC optimize ("Ofast")

using namespace std;

ifstream fin  ("mins.in");
ofstream fout ("mins.out");

const int LIMIT = 5005;
int ciur[LIMIT];
int c, d;
long long sol;

int main (){
    ios_base::sync_with_stdio(false);
    fin.tie(nullptr);
    fout.tie(nullptr);

    fin>>c>>d;
    if(--c > --d)
        swap(c, d);

    sol = (long long)c * d;
    for(int i=2; i<=c; i++){

        if(ciur[i] == 0){
            for(int j=i; j<=c; j+=i)
                if(ciur[j] != -1)
                    ciur[j]++;

            for(int j=i*i; j<=c; j+=i*i)
                ciur[j] = -1;
        }

        if(ciur[i] != -1){
            if(ciur[i]&1)
                sol -= (long long)(c / i) * (d / i);
            else
                sol += (long long)(c / i) * (d / i);
        }
    }
    fout<<sol;
    return 0;
}