import java.io.; import java.util.;

public class Solution {

public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    while(n--!=0){
        long a=sc.nextLong();
        long b=sc.nextLong();
        long and=a;
        if(a%4==0){
            for(long i=a+4;i<=b;i+=4){
                and&=i;
            }
        }
        else if(a%2==0){
            for(long i=a+2;i<=b;i+=2){
                and&=i;
            }
        }
        else{
            for(long i=a+1;i<=b;i++){
                and&=i;
            }
        }
        System.out.println(and);
    }
}

}