#include <iostream>
#include<math.h>
#include <iomanip>
#include<cstdio>
#include<string>
#include<map>
#include<vector>
#include<list>
#include<algorithm>
#include<stdlib.h>
#include<iterator>
#include<sstream>
#include<string.h>
#include<stdio.h>
using namespace std;
int gcd(int a,int b)
{
    int big=a;
    int smal=b;
    int ck;
    if(big<smal)
    {
        ck=a;
        a=b;
        b=a;
    }
    int temp;
    while(smal>0)
    {
        temp=big%smal;
        big=smal;
        smal=temp;
    }
    return big;
}


int main()
{
    int n;
    cin>>n;
    while(n--)
    {
        int a,b,c;
        cin>>a>>b;
        for(int i=2*b;i<1000000;i=i+b)
        {
            if(gcd(a,i)==b)//暴力寻找
            {
                c=i;
                break;
            }
        }
        cout<<c<<endl;
    }
    return 0;
}