#include<cstdio>
#define MAX_N 1000000
#define MAX_LEN 380000
#define MAX_K 7
using namespace std;

int a[MAX_K+1][MAX_LEN+1];
int nrdiv[MAX_N+1], len[MAX_K+1], n, T;

void ciur(int n) {
    nrdiv[1] = 0;
    a[1][len[1]++] = 1;
    for(int i = 2; i <= n; i++) {
        if(nrdiv[i] == 0)
            for(int j = i; j <= n; j += i)
                nrdiv[j]++;
        a[nrdiv[i]][len[nrdiv[i]]++] = i;
    }
}

int binarySearch(int k, int x) {
    int b, e, mid, pos;
    b = 0; e = len[k]; pos = -1;
    while(b <= e) {
        mid = (b + e) >> 1;
        if(a[k][mid] <= x) {
            pos = mid;
            b = mid + 1;
        } else e = mid - 1;
    }
    return pos;
}

int main() {
    int i, x, y, poz;
    FILE* fin, *fout;
    fin = fopen("divprim.in","r");
    fout = fopen("divprim.out","w");
    fscanf(fin,"%d",&T);
    ciur(MAX_N);
    for(i = 1; i <= T; i++) {
        fscanf(fin,"%d%d",&x,&y);
        poz = binarySearch(y,x);
        if(poz != -1)
            fprintf(fout,"%d\n",a[y][poz]);
        else fprintf(fout,"0\n");
    }
    fclose(fin);
    fclose(fout);
    return 0;
}