#include <fstream>
#define MAXD 1000000
#define INF 1000000000000000000
using namespace std;
ifstream cin ("frac.in");
ofstream cout ("frac.out");
int dv[MAXD + 10], cntDiv;
long long cntVal(long long x)
{
    long long ans = 0;
    for (int conf = 1; conf < (1 << cntDiv); conf++)
    {
        int ok = 0, cnt = 0;
        long long divi = 1;
        for (int i = 0; i < cntDiv && ok == 0; i++)
            if ((1 << i) & conf)
            {
                cnt++;
                divi = divi * dv[i + 1];
                if (divi >= x)
                    ok = 1;
            }
        if (cnt % 2 == 1)
            ans = ans + x / divi;
        else
            ans = ans - x / divi;
    }
    return ans;
}
int main()
{
    long long n, p;
    cin >> n >> p;
    int d = 2;
    while (d * d <= n)
    {
        int is = 0;
        while (n % d == 0)
        {
            n = n / d;
            is = 1;
        }
        if (is == 1)
        {
            cntDiv++;
            dv[cntDiv] = d;
        }
        d++;
    }
    if (n != 1)
    {
        cntDiv++;
        dv[cntDiv] = n;
    }
    long long left = 1, right = INF, ans = -1;
    while (left <= right)
    {
        long long mid = (left + right) / 2;
        if (p > mid - cntVal(mid))
            left = mid + 1;
        else
        {
            right = mid - 1;
            ans = mid;
        }
    }
    cout << ans;
    return 0;
}