#include<stdio.h>

int gcd(int m,int n)
{
    int t;
    while(n)
    {
        t=m;
        m=n;
        n=t%n;
    }
    return m;
}

int main()
{
    int n,a,b,c;
    scanf("%d",&n);
    while(n--)
    {
        scanf("%d%d",&a,&b);
		c=2*b;
		while(gcd(a,c)!=b)
			  c+=b;
		printf("%d\n",c);
		
    }
    return 0;
}