#include<map>
#include<set>
#include<cmath>
#include<queue>
#include<bitset>
#include<math.h>
#include<vector>
#include<string>
#include<stdio.h>
#include<cstring>
#include<iostream>
#include<algorithm>
#pragma comment(linker, "/STACK:102400000,102400000")
using namespace std;
const int N=40010;
const int mod=100000000;
const int MOD1=1000000007;
const int MOD2=1000000009;
const double EPS=0.00000001;
typedef long long ll;
const ll MOD=1000000007;
const int MAX=2000000010;
const ll INF=1ll<<55;
const double pi=acos(-1.0);
typedef double db;
typedef unsigned long long ull;
int k,a[N],q[N],f[N];
void deal(int n) {int i,j;k=0;for (i=2;i<=n;i++) {if (!q[i]) a[++k]=i;for (j=1;j<=k;j++) {if (a[j]*i>n) break ;q[a[j]*i]=1;if (i%a[j]==0) break ;}}
}
int main()
{int i,t,l,r,mid;ll n,d,g;scanf("%d", &t);deal(40000);while (t--) {scanf("%I64d%I64d", &n, &d);if (d>=n||d*2ll>=n) printf("0\n");else {for (i=1;i<=3450&&a[i]<=n/d;i++)if (a[i]>d||d%a[i]==0) break ;if (a[i]>d) g=1ll*a[i-1];else g=1ll*a[i];l=1;r=k;mid=(l+r)>>1;while (l+1<r)if (1ll*a[mid]>g||1ll*a[mid]*d>=n) { r=mid;mid=(l+r)>>1; }else { l=mid;mid=(l+r)>>1; }printf("%d\n", l);}}return 0;
}