#include <fstream>

using namespace std;

ifstream cin("divprim.in");
ofstream cout("divprim.out");

const int DIM=1000000;
const int DIM_MATRIX=380000;

int    v[DIM+1];
int    ma[8][DIM_MATRIX];
int    t,n,k;

int main()
{
    int left,right,mid,sol,j;
    for(int i=0 ; i < 8;i++)
        ma[i][0]=1; /// counter of numbers

    v[1]=0;
    ma[v[1]][ma[v[0]][0]++]=1;

    for(int i=2; i<=DIM; i++)
    {
        if(v[i]==0)
        {
            for(int j=i; j<=DIM; j+=i)
            {
                v[j]++;
            }
        }
        if(v[i]<=7)
            ma[v[i]][ma[v[i]][0]++]=i;
    }
    cin >>t;
    for(int i=1; i<=t; i++)
    {
        cin >>n>>k;
        left = 1;
        right =  ma[k][0]-1;/// nr divizori primi
        sol=0;
        while(left<=right)
        {
            mid = (left+ right)/2;
            if(ma[k][mid]==n)
            {
                sol =  ma[k][mid];
                break;
            }
            else if(ma[k][mid]<n)
            {
                sol = ma[k][mid];
                left = mid+1;
            }
            else
                right = mid -1;
        }
        cout <<sol<<endl;
    }
    return 0;
}