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

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

const int Dim = 120000001;
int Cmmdc(int a, int b);

int main()
{
	int N, P;
	fin >> N >> P;

	int cnt = 0;
    for (int i = 1; i <= Dim; ++i)
    {
        if (Cmmdc(N, i) == 1)
            cnt++;
        if (cnt == P)
        {
            fout << i;
            return 0;
        }
    }

	return 0;
}

int Cmmdc(int a, int b)
{
	int rest;
	while (b)
	{
		rest = a % b;
		a = b;
		b = rest;
	}
	return a;
}