#include <iostream>
#include <fstream>
using namespace std;

int cufar[1000001], verif[1000001];
int i, j, a, p, n, k;
long long s;

int main()
{
    ifstream f("cufar.in");
    ofstream g("cufar.out");
    f>>p>>n;

    for(i=1; i<= n; i++)
    {
        f>>a>>k;
        cufar[a] = k;
    }

    for(i = 2; i<= 1000001; i++)
        if(verif[i]==0)
            for(j=i; j<= 1000001; j=j+i)
                {
                    verif[j]++;
                    if(verif[j] == cufar[j])
                        s=s+i;
                }




    g<<s;

    return 0;
}