#include <iostream>
#include <cstdio>
#include <cmath>
#include <string>
#include <cstring>
#include <algorithm>
#include <queue>
#include <map>
#include <set>
#include <stack>
#include <vector>
#include <sstream>
#define PI acos(-1.0)
#define eps 1e-8
#define f 1000010
const int  inf =  (1<<30) - 10;
using namespace std;

int s[f], p;
int num[f];
int dp[f][8];

void get_prime()
{
	int i,j,n,m,s1,s2,a,b;
	s[1]=2;
	s[2]=3;
	m=2;
	for(i=6;i<f;i=i+6)
	{
		a=i-1;
		b=i+1;
		s1=1;
		s2=1;
		n=(int)sqrt(m);
		for(j=1;j<=n+1;j++)
			if(a%s[j]==0){s1=0;break;}
		for(j=1;j<=n+1;j++)
			if(b%s[j]==0){s2=0;break;}
		if(s1!=0){m++;s[m]=a;}
		if(s2!=0){m++;s[m]=b;}
	}
	p = m;
}

void init(){
    memset(num,0,sizeof(num));
    memset(dp,0,sizeof(dp));
    for(int i = 1;i <= p; ++i){
        for(int j = 1;j*s[i] <= 1000000; ++j){
            num[j*s[i]]++;
        }
    }
    for(int i = 2;i <= 1000000; ++i){
        for(int j = 1;j <= 7; ++j){
            dp[i][j] = dp[i-1][j];
        }
        dp[i][num[i]]++;
    }
}

int main(){
    //freopen("input.txt","r",stdin);
    get_prime();
    init();
    int T;
    cin>>T;
    int l, r;
    while(T--){
        scanf("%d %d",&l,&r);
        int knum[8];
        for(int i = 1;i <= 7; ++i){
            knum[i] = dp[r][i] - dp[l-1][i];
        }
        if(knum[7] >= 2){
            printf("7\n");
        }else if(knum[6]>=2){
            printf("6\n");
        }else if(knum[5]>=2){
            printf("5\n");
        }else if(knum[4]>=2){
            printf("4\n");
        }else if(knum[3]>=2){
            printf("3\n");
        }else if(knum[6] && knum[3]){
            printf("3\n");
        }else if(knum[2]>=2){
            printf("2\n");
        }else if(knum[6] && knum[2]){
            printf("2\n");
        }else if(knum[4] && knum[2]){
            printf("2\n");
        }else{
            printf("1\n");
        }
    }
    return 0;
}

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