#include<stdio.h>
int gcd(int a, int b)
{
    if(b == 0) 
	    return a;
    else
        return gcd(b, a%b);
}
int main()
{
    int t, a, b, c;
    scanf("%d", &t);
    while(t --){
        scanf("%d%d", &a, &b);
        c= b*2;
        while(gcd(a, c) != b){
            c+=b;
        }
        printf("%d\n", c);
    }
    return 0;
}