#include <iostream>
#include <fstream>
#include <vector>

#define NMAX 1000000
using namespace std;
ifstream fi("cufar.in");
ofstream fo("cufar.out");

int N;
int P;
int MAXX;
bool ciur[NMAX];
long long nrprime[NMAX + 5][11];

int poz[NMAX];


vector<int> primes;

pair<int, int> num[NMAX];


void MakeCiur()
{
    for(int i = 2; i <= NMAX; ++i)
    {
        if(!ciur[i])
        {
            poz[i] ++;
            nrprime[i][poz[i]] = i;
            for(int j = i + i; j <= NMAX; j += i)
            {
                nrprime[j][++poz[j]] = i;
                ciur[j] = 1;
            }
        }
    }
}

int main()
{
    fi >> P >> N;
    int a, b;
    MakeCiur();
    long long sum = 0;
    for(int i = 1; i <= N; ++i)
    {
        fi >> a >> b;
        sum += nrprime[a][b];
    }
    fo << sum;

}