#include<fstream>
#include<vector>
using namespace std;
vector<int>v(1000002,0);
vector<int>haha[8];
int n;
ifstream f("divprim.in");
ofstream g("divprim.out");
void ciur()
{
	int i,j;
	for(i=2;i<=500000;i++)
	{
		if(v[i]==0)
			for(j=1;j*i<=1000000;j++)
				v[i*j]++;
		haha[v[i]].push_back(i);
	}
}
int cautare_binara(int i,int st,int dr,int x)
{
	int mij=(st+dr)/2;
	if(st<dr)
	{
		if(haha[i][mij]<x)
			return cautare_binara(i,mij+1,dr,x);
		else
			if(haha[i][mij]>x)
				return cautare_binara(i,st,mij-1,x);
	}
	return mij;
}
int main()
{
	int poz,i,N,K,T,lungime;
	for(i=0;i<=7;i++)
		haha[i].push_back(0);
	ciur();
	haha[0].push_back(1);
	f>>T;
	for(i=1;i<=T;i++)
	{
		f>>N>>K;
		lungime=haha[K].size()-1;
		poz=cautare_binara(K,1,lungime,N);
		if(haha[K][poz]<=N)
			g<<haha[K][poz]<<endl;
		else
			g<<haha[K][poz-1]<<endl;
	}
	f.close();g.close();
	return 0;
}